Merge pull request #7061 from ethereum-optimism/inphi/fdg-rez

feat(ctb): Rework FaultDisputeGame resolution

op-challenger/game/fault/agent.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"sync"
 
 	"github.com/ethereum-optimism/optimism/op-challenger/game/fault/solver"
 	"github.com/ethereum-optimism/optimism/op-challenger/game/fault/types"
@@ -18,6 +19,8 @@ import (
 type Responder interface {
 	CallResolve(ctx context.Context) (gameTypes.GameStatus, error)
 	Resolve(ctx context.Context) error
+	CallResolveClaim(ctx context.Context, claimIdx uint64) error
+	ResolveClaim(ctx context.Context, claimIdx uint64) error
 	PerformAction(ctx context.Context, action types.Action) error
 }
 
@@ -112,6 +115,10 @@ func (a *Agent) shouldResolve(status gameTypes.GameStatus) bool {
 // tryResolve resolves the game if it is in a winning state
 // Returns true if the game is resolvable (regardless of whether it was actually resolved)
 func (a *Agent) tryResolve(ctx context.Context) bool {
+	if err := a.resolveClaims(ctx); err != nil {
+		a.log.Error("Failed to resolve claims", "err", err)
+		return false
+	}
 	status, err := a.responder.CallResolve(ctx)
 	if err != nil || status == gameTypes.GameStatusInProgress {
 		return false
@@ -126,6 +133,60 @@ func (a *Agent) tryResolve(ctx context.Context) bool {
 	return true
 }
 
+var errNoResolvableClaims = errors.New("no resolvable claims")
+
+func (a *Agent) tryResolveClaims(ctx context.Context) error {
+	claims, err := a.loader.FetchClaims(ctx)
+	if err != nil {
+		return fmt.Errorf("failed to fetch claims: %w", err)
+	}
+	if len(claims) == 0 {
+		return errNoResolvableClaims
+	}
+
+	var resolvableClaims []int64
+	for _, claim := range claims {
+		a.log.Debug("checking if claim is resolvable", "claimIdx", claim.ContractIndex)
+		if err := a.responder.CallResolveClaim(ctx, uint64(claim.ContractIndex)); err == nil {
+			a.log.Info("Resolving claim", "claimIdx", claim.ContractIndex)
+			resolvableClaims = append(resolvableClaims, int64(claim.ContractIndex))
+		}
+	}
+	a.log.Info("Resolving claims", "numClaims", len(resolvableClaims))
+	if len(resolvableClaims) == 0 {
+		return errNoResolvableClaims
+	}
+
+	var wg sync.WaitGroup
+	wg.Add(len(resolvableClaims))
+	for _, claimIdx := range resolvableClaims {
+		claimIdx := claimIdx
+		go func() {
+			defer wg.Done()
+			err := a.responder.ResolveClaim(ctx, uint64(claimIdx))
+			if err != nil {
+				a.log.Error("Failed to resolve claim", "err", err)
+			}
+		}()
+	}
+	wg.Wait()
+	return nil
+}
+
+func (a *Agent) resolveClaims(ctx context.Context) error {
+	for {
+		err := a.tryResolveClaims(ctx)
+		switch err {
+		case errNoResolvableClaims:
+			return nil
+		case nil:
+			continue
+		default:
+			return err
+		}
+	}
+}
+
 // newGameFromContracts initializes a new game state from the state in the contract
 func (a *Agent) newGameFromContracts(ctx context.Context) (types.Game, error) {
 	claims, err := a.loader.FetchClaims(ctx)

op-challenger/game/fault/agent_test.go

@@ -77,7 +77,7 @@ func TestDoNotMakeMovesWhenGameIsResolvable(t *testing.T) {
 			require.NoError(t, agent.Act(ctx))
 
 			require.Equal(t, 1, responder.callResolveCount, "should check if game is resolvable")
-			require.Zero(t, claimLoader.callCount, "should not fetch claims for resolvable game")
+			require.Equal(t, 1, claimLoader.callCount, "should fetch claims once for resolveClaim")
 
 			if test.shouldResolve {
 				require.EqualValues(t, 1, responder.resolveCount, "should resolve winning game")
@@ -92,6 +92,7 @@ func TestLoadClaimsWhenGameNotResolvable(t *testing.T) {
 	// Checks that if the game isn't resolvable, that the agent continues on to start checking claims
 	agent, claimLoader, responder := setupTestAgent(t, false)
 	responder.callResolveErr = errors.New("game is not resolvable")
+	responder.callResolveClaimErr = errors.New("claim is not resolvable")
 	depth := 4
 	claimBuilder := test.NewClaimBuilder(t, depth, alphabet.NewTraceProvider("abcdefg", uint64(depth)))
 
@@ -101,7 +102,9 @@ func TestLoadClaimsWhenGameNotResolvable(t *testing.T) {
 
 	require.NoError(t, agent.Act(context.Background()))
 
-	require.EqualValues(t, 1, claimLoader.callCount, "should load claims for unresolvable game")
+	require.EqualValues(t, 2, claimLoader.callCount, "should load claims for unresolvable game")
+	require.EqualValues(t, responder.callResolveClaimCount, 1, "should check if claim is resolvable")
+	require.Zero(t, responder.resolveClaimCount, "should not send resolveClaim")
 }
 
 func setupTestAgent(t *testing.T, agreeWithProposedOutput bool) (*Agent, *stubClaimLoader, *stubResponder) {
@@ -132,6 +135,10 @@ type stubResponder struct {
 
 	resolveCount int
 	resolveErr   error
+
+	callResolveClaimCount int
+	callResolveClaimErr   error
+	resolveClaimCount     int
 }
 
 func (s *stubResponder) CallResolve(ctx context.Context) (gameTypes.GameStatus, error) {
@@ -144,8 +151,18 @@ func (s *stubResponder) Resolve(ctx context.Context) error {
 	return s.resolveErr
 }
 
+func (s *stubResponder) CallResolveClaim(ctx context.Context, clainIdx uint64) error {
+	s.callResolveClaimCount++
+	return s.callResolveClaimErr
+}
+
+func (s *stubResponder) ResolveClaim(ctx context.Context, clainIdx uint64) error {
+	s.resolveClaimCount++
+	return nil
+}
+
 func (s *stubResponder) PerformAction(ctx context.Context, response types.Action) error {
-	panic("Not implemented")
+	return nil
 }
 
 type stubUpdater struct {

op-challenger/game/fault/responder/responder.go

@@ -94,6 +94,34 @@ func (r *FaultResponder) Resolve(ctx context.Context) error {
 	return r.sendTxAndWait(ctx, txData)
 }
 
+// buildResolveClaimData creates the transaction data for the ResolveClaim function.
+func (r *FaultResponder) buildResolveClaimData(ctx context.Context, claimIdx uint64) ([]byte, error) {
+	return r.fdgAbi.Pack("resolveClaim", big.NewInt(int64(claimIdx)))
+}
+
+// CallResolveClaim determines if the resolveClaim function on the fault dispute game contract
+// would succeed.
+func (r *FaultResponder) CallResolveClaim(ctx context.Context, claimIdx uint64) error {
+	txData, err := r.buildResolveClaimData(ctx, claimIdx)
+	if err != nil {
+		return err
+	}
+	_, err = r.txMgr.Call(ctx, ethereum.CallMsg{
+		To:   &r.fdgAddr,
+		Data: txData,
+	}, nil)
+	return err
+}
+
+// ResolveClaim executes a resolveClaim transaction to resolve a fault dispute game.
+func (r *FaultResponder) ResolveClaim(ctx context.Context, claimIdx uint64) error {
+	txData, err := r.buildResolveClaimData(ctx, claimIdx)
+	if err != nil {
+		return err
+	}
+	return r.sendTxAndWait(ctx, txData)
+}
+
 func (r *FaultResponder) PerformAction(ctx context.Context, action types.Action) error {
 	var txData []byte
 	var err error

op-challenger/game/fault/responder/responder_test.go

@@ -73,6 +73,40 @@ func TestResolve(t *testing.T) {
 	})
 }
 
+func TestCallResolveClaim(t *testing.T) {
+	t.Run("SendFails", func(t *testing.T) {
+		responder, mockTxMgr := newTestFaultResponder(t)
+		mockTxMgr.callFails = true
+		err := responder.CallResolveClaim(context.Background(), 0)
+		require.ErrorIs(t, err, mockCallError)
+		require.Equal(t, 0, mockTxMgr.calls)
+	})
+
+	t.Run("Success", func(t *testing.T) {
+		responder, mockTxMgr := newTestFaultResponder(t)
+		err := responder.CallResolveClaim(context.Background(), 0)
+		require.NoError(t, err)
+		require.Equal(t, 1, mockTxMgr.calls)
+	})
+}
+
+func TestResolveClaim(t *testing.T) {
+	t.Run("SendFails", func(t *testing.T) {
+		responder, mockTxMgr := newTestFaultResponder(t)
+		mockTxMgr.sendFails = true
+		err := responder.ResolveClaim(context.Background(), 0)
+		require.ErrorIs(t, err, mockSendError)
+		require.Equal(t, 0, mockTxMgr.sends)
+	})
+
+	t.Run("Success", func(t *testing.T) {
+		responder, mockTxMgr := newTestFaultResponder(t)
+		err := responder.ResolveClaim(context.Background(), 0)
+		require.NoError(t, err)
+		require.Equal(t, 1, mockTxMgr.sends)
+	})
+}
+
 // TestRespond tests the [Responder.Respond] method.
 func TestPerformAction(t *testing.T) {
 	t.Run("send fails", func(t *testing.T) {

op-challenger/game/fault/solver/game_solver.go

@@ -48,7 +48,10 @@ func (s *GameSolver) calculateStep(ctx context.Context, game types.Game, claim t
 	if game.AgreeWithClaimLevel(claim) {
 		return nil, nil
 	}
-	step, err := s.claimSolver.AttemptStep(ctx, claim, game.AgreeWithClaimLevel(claim))
+	step, err := s.claimSolver.AttemptStep(ctx, game, claim)
+	if err == ErrStepIgnoreInvalidPath {
+		return nil, nil
+	}
 	if err != nil {
 		return nil, err
 	}
@@ -63,11 +66,14 @@ func (s *GameSolver) calculateStep(ctx context.Context, game types.Game, claim t
 }
 
 func (s *GameSolver) calculateMove(ctx context.Context, game types.Game, claim types.Claim) (*types.Action, error) {
-	move, err := s.claimSolver.NextMove(ctx, claim, game.AgreeWithClaimLevel(claim))
+	if game.AgreeWithClaimLevel(claim) {
+		return nil, nil
+	}
+	move, err := s.claimSolver.NextMove(ctx, claim, game)
 	if err != nil {
 		return nil, fmt.Errorf("failed to calculate next move for claim index %v: %w", claim.ContractIndex, err)
 	}
-	if move == nil || game.IsDuplicate(move.ClaimData) {
+	if move == nil || game.IsDuplicate(*move) {
 		return nil, nil
 	}
 	return &types.Action{

op-challenger/game/fault/solver/game_solver_test.go

@@ -48,7 +48,6 @@ func TestCalculateNextActions(t *testing.T) {
 			rootClaimCorrect:    true,
 			setupGame:           func(builder *faulttest.GameBuilder) {},
 		},
-
 		{
 			name:                "DoNotPerformDuplicateMoves",
 			agreeWithOutputRoot: true,
@@ -93,16 +92,15 @@ func TestCalculateNextActions(t *testing.T) {
 				maliciousStateHash := common.Hash{0x01, 0xaa}
 
 				// Dishonest actor counters their own claims to set up a situation with an invalid prestate
-				// The honest actor should attack all claims that support the root claim (disagree with the output root)
-				builder.Seq().ExpectAttack(). // This expected action is the winning move.
-								Attack(maliciousStateHash).
-								Defend(maliciousStateHash).ExpectAttack().
-								Attack(maliciousStateHash).
-								Attack(maliciousStateHash).ExpectStepAttack()
-
-				// The attempt to step against our malicious leaf node will fail because the pre-state won't match our
-				// malicious state hash. However, it is the very first expected action, attacking the root claim with
-				// the correct hash that wins the game since it will be the left-most uncountered claim.
+				// The honest actor should ignore path created by the dishonest actor, only supporting its own attack on the root claim
+				honestMove := builder.Seq().AttackCorrect() // This expected action is the winning move.
+				dishonestMove := honestMove.Attack(maliciousStateHash)
+				// The expected action by the honest actor
+				dishonestMove.ExpectAttack()
+				// The honest actor will ignore this poisoned path
+				dishonestMove.
+					Defend(maliciousStateHash).
+					Attack(maliciousStateHash)
 			},
 		},
 	}

op-challenger/game/fault/solver/rules.go

@@ -13,7 +13,6 @@ var rules = []actionRule{
 	parentMustExist,
 	onlyStepAtMaxDepth,
 	onlyMoveBeforeMaxDepth,
-	onlyCounterClaimsAtDisagreeingLevels,
 	doNotDuplicateExistingMoves,
 	doNotDefendRootClaim,
 }
@@ -57,20 +56,12 @@ func onlyMoveBeforeMaxDepth(game types.Game, action types.Action) error {
 	return nil
 }
 
-func onlyCounterClaimsAtDisagreeingLevels(game types.Game, action types.Action) error {
-	parentClaim := game.Claims()[action.ParentIdx]
-	if game.AgreeWithClaimLevel(parentClaim) {
-		return fmt.Errorf("countering a claim at depth %v that supports our view of the root", parentClaim.Position.Depth())
-	}
-	return nil
-}
-
 func doNotDuplicateExistingMoves(game types.Game, action types.Action) error {
 	newClaimData := types.ClaimData{
 		Value:    action.Value,
 		Position: resultingPosition(game, action),
 	}
-	if game.IsDuplicate(newClaimData) {
+	if game.IsDuplicate(types.Claim{ClaimData: newClaimData, ParentContractIndex: action.ParentIdx}) {
 		return fmt.Errorf("creating duplicate claim at %v with value %v", newClaimData.Position.ToGIndex(), newClaimData.Value)
 	}
 	return nil

op-challenger/game/fault/solver/solver.go

@@ -11,8 +11,9 @@ import (
 )
 
 var (
-	ErrStepNonLeafNode = errors.New("cannot step on non-leaf claims")
-	ErrStepAgreedClaim = errors.New("cannot step on claims we agree with")
+	ErrStepNonLeafNode       = errors.New("cannot step on non-leaf claims")
+	ErrStepAgreedClaim       = errors.New("cannot step on claims we agree with")
+	ErrStepIgnoreInvalidPath = errors.New("cannot step on claims that dispute invalid paths")
 )
 
 // claimSolver uses a [TraceProvider] to determine the moves to make in a dispute game.
@@ -30,10 +31,7 @@ func newClaimSolver(gameDepth int, traceProvider types.TraceProvider) *claimSolv
 }
 
 // NextMove returns the next move to make given the current state of the game.
-func (s *claimSolver) NextMove(ctx context.Context, claim types.Claim, agreeWithClaimLevel bool) (*types.Claim, error) {
-	if agreeWithClaimLevel {
-		return nil, nil
-	}
+func (s *claimSolver) NextMove(ctx context.Context, claim types.Claim, game types.Game) (*types.Claim, error) {
 	if claim.Depth() == s.gameDepth {
 		return nil, types.ErrGameDepthReached
 	}
@@ -41,6 +39,24 @@ func (s *claimSolver) NextMove(ctx context.Context, claim types.Claim, agreeWith
 	if err != nil {
 		return nil, err
 	}
+
+	// Before challenging this claim, first check that the move wasn't warranted.
+	// If the parent claim is on a dishonest path, then we would have moved against it anyways. So we don't move.
+	// Avoiding dishonest paths ensures that there's always a valid claim available to support ours during step.
+	if !claim.IsRoot() {
+		parent, err := game.GetParent(claim)
+		if err != nil {
+			return nil, err
+		}
+		agreeWithParent, err := s.agreeWithClaimPath(ctx, game, parent)
+		if err != nil {
+			return nil, err
+		}
+		if !agreeWithParent {
+			return nil, nil
+		}
+	}
+
 	if agree {
 		return s.defend(ctx, claim)
 	} else {
@@ -58,13 +74,25 @@ type StepData struct {
 
 // AttemptStep determines what step should occur for a given leaf claim.
 // An error will be returned if the claim is not at the max depth.
-func (s *claimSolver) AttemptStep(ctx context.Context, claim types.Claim, agreeWithClaimLevel bool) (StepData, error) {
+// Returns ErrStepIgnoreInvalidPath if the claim disputes an invalid path
+func (s *claimSolver) AttemptStep(ctx context.Context, game types.Game, claim types.Claim) (StepData, error) {
 	if claim.Depth() != s.gameDepth {
 		return StepData{}, ErrStepNonLeafNode
 	}
-	if agreeWithClaimLevel {
-		return StepData{}, ErrStepAgreedClaim
+
+	// Step only on claims that dispute a valid path
+	parent, err := game.GetParent(claim)
+	if err != nil {
+		return StepData{}, err
 	}
+	parentValid, err := s.agreeWithClaimPath(ctx, game, parent)
+	if err != nil {
+		return StepData{}, err
+	}
+	if !parentValid {
+		return StepData{}, ErrStepIgnoreInvalidPath
+	}
+
 	claimCorrect, err := s.agreeWithClaim(ctx, claim.ClaimData)
 	if err != nil {
 		return StepData{}, err
@@ -142,3 +170,26 @@ func (s *claimSolver) traceAtPosition(ctx context.Context, p types.Position) (co
 	hash, err := s.trace.Get(ctx, index)
 	return hash, err
 }
+
+// agreeWithClaimPath returns true if the every other claim in the path to root is correct according to the internal [TraceProvider].
+func (s *claimSolver) agreeWithClaimPath(ctx context.Context, game types.Game, claim types.Claim) (bool, error) {
+	agree, err := s.agreeWithClaim(ctx, claim.ClaimData)
+	if err != nil {
+		return false, err
+	}
+	if !agree {
+		return false, nil
+	}
+	if claim.IsRoot() || claim.Parent.IsRootPosition() {
+		return true, nil
+	}
+	parent, err := game.GetParent(claim)
+	if err != nil {
+		return false, err
+	}
+	grandParent, err := game.GetParent(parent)
+	if err != nil {
+		return false, err
+	}
+	return s.agreeWithClaimPath(ctx, game, grandParent)
+}

op-challenger/game/fault/test/claim_builder.go

@@ -79,12 +79,13 @@ func (c *ClaimBuilder) claim(idx uint64, correct bool) common.Hash {
 
 func (c *ClaimBuilder) CreateRootClaim(correct bool) types.Claim {
 	value := c.claim((1<<c.maxDepth)-1, correct)
-	return types.Claim{
+	claim := types.Claim{
 		ClaimData: types.ClaimData{
 			Value:    value,
 			Position: types.NewPosition(0, 0),
 		},
 	}
+	return claim
 }
 
 func (c *ClaimBuilder) CreateLeafClaim(traceIndex uint64, correct bool) types.Claim {

op-challenger/game/fault/types/game.go

@@ -23,8 +23,12 @@ type Game interface {
 	// Claims returns all of the claims in the game.
 	Claims() []Claim
 
-	// IsDuplicate returns true if the provided [Claim] already exists in the game state.
-	IsDuplicate(claim ClaimData) bool
+	// GetParent returns the parent of the provided claim.
+	GetParent(claim Claim) (Claim, error)
+
+	// IsDuplicate returns true if the provided [Claim] already exists in the game state
+	// referencing the same parent claim
+	IsDuplicate(claim Claim) bool
 
 	// AgreeWithClaimLevel returns if the game state agrees with the provided claim level.
 	AgreeWithClaimLevel(claim Claim) bool
@@ -32,31 +36,37 @@ type Game interface {
 	MaxDepth() uint64
 }
 
+type claimEntry struct {
+	ClaimData
+	ParentContractIndex int
+}
+
 type extendedClaim struct {
 	self     Claim
-	children []ClaimData
+	children []claimEntry
 }
 
 // gameState is a struct that represents the state of a dispute game.
 // The game state implements the [Game] interface.
 type gameState struct {
 	agreeWithProposedOutput bool
-	root                    ClaimData
-	claims                  map[ClaimData]*extendedClaim
+	root                    claimEntry
+	claims                  map[claimEntry]*extendedClaim
 	depth                   uint64
 }
 
 // NewGameState returns a new game state.
 // The provided [Claim] is used as the root node.
 func NewGameState(agreeWithProposedOutput bool, root Claim, depth uint64) *gameState {
-	claims := make(map[ClaimData]*extendedClaim)
-	claims[root.ClaimData] = &extendedClaim{
+	claims := make(map[claimEntry]*extendedClaim)
+	rootClaimEntry := makeClaimEntry(root)
+	claims[rootClaimEntry] = &extendedClaim{
 		self:     root,
-		children: make([]ClaimData, 0),
+		children: make([]claimEntry, 0),
 	}
 	return &gameState{
 		agreeWithProposedOutput: agreeWithProposedOutput,
-		root:                    root.ClaimData,
+		root:                    rootClaimEntry,
 		claims:                  claims,
 		depth:                   depth,
 	}
@@ -87,29 +97,29 @@ func (g *gameState) PutAll(claims []Claim) error {
 
 // Put adds a claim into the game state.
 func (g *gameState) Put(claim Claim) error {
-	if claim.IsRoot() || g.IsDuplicate(claim.ClaimData) {
+	if claim.IsRoot() || g.IsDuplicate(claim) {
 		return ErrClaimExists
 	}
-	parent, ok := g.claims[claim.Parent]
-	if !ok {
+
+	parent := g.getParent(claim)
+	if parent == nil {
 		return errors.New("no parent claim")
-	} else {
-		parent.children = append(parent.children, claim.ClaimData)
 	}
-	g.claims[claim.ClaimData] = &extendedClaim{
+	parent.children = append(parent.children, makeClaimEntry(claim))
+	g.claims[makeClaimEntry(claim)] = &extendedClaim{
 		self:     claim,
-		children: make([]ClaimData, 0),
+		children: make([]claimEntry, 0),
 	}
 	return nil
 }
 
-func (g *gameState) IsDuplicate(claim ClaimData) bool {
-	_, ok := g.claims[claim]
+func (g *gameState) IsDuplicate(claim Claim) bool {
+	_, ok := g.claims[makeClaimEntry(claim)]
 	return ok
 }
 
 func (g *gameState) Claims() []Claim {
-	queue := []ClaimData{g.root}
+	queue := []claimEntry{g.root}
 	var out []Claim
 	for len(queue) > 0 {
 		item := queue[0]
@@ -124,17 +134,34 @@ func (g *gameState) MaxDepth() uint64 {
 	return g.depth
 }
 
-func (g *gameState) getChildren(c ClaimData) []ClaimData {
+func (g *gameState) getChildren(c claimEntry) []claimEntry {
 	return g.claims[c].children
 }
 
-func (g *gameState) getParent(claim Claim) (Claim, error) {
-	if claim.IsRoot() {
+func (g *gameState) GetParent(claim Claim) (Claim, error) {
+	parent := g.getParent(claim)
+	if parent == nil {
 		return Claim{}, ErrClaimNotFound
 	}
-	if parent, ok := g.claims[claim.Parent]; !ok {
-		return Claim{}, ErrClaimNotFound
-	} else {
-		return parent.self, nil
+	return parent.self, nil
+}
+
+func (g *gameState) getParent(claim Claim) *extendedClaim {
+	if claim.IsRoot() {
+		return nil
+	}
+	// TODO(inphi): refactor gameState for faster parent lookups
+	for _, c := range g.claims {
+		if c.self.ContractIndex == claim.ParentContractIndex {
+			return c
+		}
+	}
+	return nil
+}
+
+func makeClaimEntry(claim Claim) claimEntry {
+	return claimEntry{
+		ClaimData:           claim.ClaimData,
+		ParentContractIndex: claim.ParentContractIndex,
 	}
 }

op-challenger/game/fault/types/game_test.go

@@ -24,14 +24,18 @@ func createTestClaims() (Claim, Claim, Claim, Claim) {
 			Value:    common.HexToHash("0x0000000000000000000000000000000000000000000000000000000000000364"),
 			Position: NewPosition(1, 0),
 		},
-		Parent: root.ClaimData,
+		Parent:              root.ClaimData,
+		ContractIndex:       1,
+		ParentContractIndex: 0,
 	}
 	middle := Claim{
 		ClaimData: ClaimData{
 			Value:    common.HexToHash("0x0000000000000000000000000000000000000000000000000000000000000578"),
 			Position: NewPosition(2, 2),
 		},
-		Parent: top.ClaimData,
+		Parent:              top.ClaimData,
+		ContractIndex:       2,
+		ParentContractIndex: 1,
 	}
 
 	bottom := Claim{
@@ -39,7 +43,9 @@ func createTestClaims() (Claim, Claim, Claim, Claim) {
 			Value:    common.HexToHash("0x0000000000000000000000000000000000000000000000000000000000000465"),
 			Position: NewPosition(3, 4),
 		},
-		Parent: middle.ClaimData,
+		Parent:              middle.ClaimData,
+		ContractIndex:       3,
+		ParentContractIndex: 2,
 	}
 
 	return root, top, middle, bottom
@@ -52,12 +58,12 @@ func TestIsDuplicate(t *testing.T) {
 	require.NoError(t, g.Put(top))
 
 	// Root + Top should be duplicates
-	require.True(t, g.IsDuplicate(root.ClaimData))
-	require.True(t, g.IsDuplicate(top.ClaimData))
+	require.True(t, g.IsDuplicate(root))
+	require.True(t, g.IsDuplicate(top))
 
 	// Middle + Bottom should not be a duplicate
-	require.False(t, g.IsDuplicate(middle.ClaimData))
-	require.False(t, g.IsDuplicate(bottom.ClaimData))
+	require.False(t, g.IsDuplicate(middle))
+	require.False(t, g.IsDuplicate(bottom))
 }
 
 // TestGame_Put_RootAlreadyExists tests the [Game.Put] method using a [gameState]
@@ -104,20 +110,20 @@ func TestGame_PutAll_ParentsAndChildren(t *testing.T) {
 	g := NewGameState(false, root, testMaxDepth)
 
 	// We should not be able to get the parent of the root claim.
-	parent, err := g.getParent(root)
+	parent, err := g.GetParent(root)
 	require.ErrorIs(t, err, ErrClaimNotFound)
 	require.Equal(t, parent, Claim{})
 
 	// Put the rest of the claims in the state.
 	err = g.PutAll([]Claim{top, middle, bottom})
 	require.NoError(t, err)
-	parent, err = g.getParent(top)
+	parent, err = g.GetParent(top)
 	require.NoError(t, err)
 	require.Equal(t, parent, root)
-	parent, err = g.getParent(middle)
+	parent, err = g.GetParent(middle)
 	require.NoError(t, err)
 	require.Equal(t, parent, top)
-	parent, err = g.getParent(bottom)
+	parent, err = g.GetParent(bottom)
 	require.NoError(t, err)
 	require.Equal(t, parent, middle)
 }
@@ -145,28 +151,28 @@ func TestGame_Put_ParentsAndChildren(t *testing.T) {
 	g := NewGameState(false, root, testMaxDepth)
 
 	// We should not be able to get the parent of the root claim.
-	parent, err := g.getParent(root)
+	parent, err := g.GetParent(root)
 	require.ErrorIs(t, err, ErrClaimNotFound)
 	require.Equal(t, parent, Claim{})
 
 	// Put + Check Top
 	err = g.Put(top)
 	require.NoError(t, err)
-	parent, err = g.getParent(top)
+	parent, err = g.GetParent(top)
 	require.NoError(t, err)
 	require.Equal(t, parent, root)
 
 	// Put + Check Top Middle
 	err = g.Put(middle)
 	require.NoError(t, err)
-	parent, err = g.getParent(middle)
+	parent, err = g.GetParent(middle)
 	require.NoError(t, err)
 	require.Equal(t, parent, top)
 
 	// Put + Check Top Bottom
 	err = g.Put(bottom)
 	require.NoError(t, err)
-	parent, err = g.getParent(bottom)
+	parent, err = g.GetParent(bottom)
 	require.NoError(t, err)
 	require.Equal(t, parent, middle)
 }
@@ -194,27 +200,3 @@ func TestGame_ClaimPairs(t *testing.T) {
 	claims := g.Claims()
 	require.ElementsMatch(t, expected, claims)
 }
-
-func TestAgreeWithClaimLevelDisagreeWithOutput(t *testing.T) {
-	// Setup the game state.
-	root, top, middle, bottom := createTestClaims()
-	g := NewGameState(false, root, testMaxDepth)
-	require.NoError(t, g.PutAll([]Claim{top, middle, bottom}))
-
-	require.True(t, g.AgreeWithClaimLevel(root))
-	require.False(t, g.AgreeWithClaimLevel(top))
-	require.True(t, g.AgreeWithClaimLevel(middle))
-	require.False(t, g.AgreeWithClaimLevel(bottom))
-}
-
-func TestAgreeWithClaimLevelAgreeWithOutput(t *testing.T) {
-	// Setup the game state.
-	root, top, middle, bottom := createTestClaims()
-	g := NewGameState(true, root, testMaxDepth)
-	require.NoError(t, g.PutAll([]Claim{top, middle, bottom}))
-
-	require.False(t, g.AgreeWithClaimLevel(root))
-	require.True(t, g.AgreeWithClaimLevel(top))
-	require.False(t, g.AgreeWithClaimLevel(middle))
-	require.True(t, g.AgreeWithClaimLevel(bottom))
-}

op-e2e/e2eutils/challenger/helper.go

@@ -68,6 +68,12 @@ func WithAlphabet(alphabet string) Option {
 	}
 }
 
+func WithPollInterval(pollInterval time.Duration) Option {
+	return func(c *config.Config) {
+		c.PollInterval = pollInterval
+	}
+}
+
 func WithCannon(
 	t *testing.T,
 	rollupCfg *rollup.Config,
@@ -98,7 +104,7 @@ func WithCannon(
 }
 
 func NewChallenger(t *testing.T, ctx context.Context, l1Endpoint string, name string, options ...Option) *Helper {
-	log := testlog.Logger(t, log.LvlInfo).New("role", name)
+	log := testlog.Logger(t, log.LvlDebug).New("role", name)
 	log.Info("Creating challenger", "l1", l1Endpoint)
 	cfg := NewChallengerConfig(t, l1Endpoint, options...)
 

op-e2e/e2eutils/disputegame/alphabet_helper.go

@@ -4,6 +4,7 @@ import (
 	"context"
 
 	"github.com/ethereum-optimism/optimism/op-challenger/config"
+	"github.com/ethereum-optimism/optimism/op-challenger/game/fault/trace/alphabet"
 	"github.com/ethereum-optimism/optimism/op-e2e/e2eutils/challenger"
 
 	"github.com/ethereum/go-ethereum/common"
@@ -33,3 +34,12 @@ func (g *AlphabetGameHelper) StartChallenger(ctx context.Context, l1Endpoint str
 	})
 	return c
 }
+
+func (g *AlphabetGameHelper) CreateHonestActor(ctx context.Context, alphabetTrace string, depth uint64) *HonestHelper {
+	return &HonestHelper{
+		t:            g.t,
+		require:      g.require,
+		game:         &g.FaultGameHelper,
+		correctTrace: alphabet.NewTraceProvider(alphabetTrace, depth),
+	}
+}

op-e2e/e2eutils/disputegame/game_helper.go

@@ -2,16 +2,19 @@ package disputegame
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"math/big"
 	"testing"
 	"time"
 
 	"github.com/ethereum-optimism/optimism/op-bindings/bindings"
+	"github.com/ethereum-optimism/optimism/op-challenger/game/fault"
 	"github.com/ethereum-optimism/optimism/op-challenger/game/fault/types"
 	"github.com/ethereum-optimism/optimism/op-e2e/e2eutils/wait"
 	"github.com/ethereum/go-ethereum/accounts/abi/bind"
 	"github.com/ethereum/go-ethereum/common"
+	gethtypes "github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/ethclient"
 	"github.com/stretchr/testify/require"
 )
@@ -130,6 +133,10 @@ func (g *FaultGameHelper) getClaim(ctx context.Context, claimIdx int64) Contract
 	return claimData
 }
 
+func (g *FaultGameHelper) GetClaimUnsafe(ctx context.Context, claimIdx int64) ContractClaim {
+	return g.getClaim(ctx, claimIdx)
+}
+
 func (g *FaultGameHelper) WaitForClaimAtDepth(ctx context.Context, depth int) {
 	g.waitForClaim(
 		ctx,
@@ -169,6 +176,12 @@ func (g *FaultGameHelper) Resolve(ctx context.Context) {
 	g.require.NoError(err)
 }
 
+func (g *FaultGameHelper) Status(ctx context.Context) Status {
+	status, err := g.game.Status(&bind.CallOpts{Context: ctx})
+	g.require.NoError(err)
+	return Status(status)
+}
+
 func (g *FaultGameHelper) WaitForGameStatus(ctx context.Context, expected Status) {
 	g.t.Logf("Waiting for game %v to have status %v", g.addr, expected)
 	timedCtx, cancel := context.WithTimeout(ctx, time.Minute)
@@ -186,6 +199,46 @@ func (g *FaultGameHelper) WaitForGameStatus(ctx context.Context, expected Status
 	g.require.NoErrorf(err, "wait for game status. Game state: \n%v", g.gameData(ctx))
 }
 
+func (g *FaultGameHelper) WaitForInactivity(ctx context.Context, numInactiveBlocks int, untilGameEnds bool) {
+	g.t.Logf("Waiting for game %v to have no activity for %v blocks", g.addr, numInactiveBlocks)
+	headCh := make(chan *gethtypes.Header, 100)
+	headSub, err := g.client.SubscribeNewHead(ctx, headCh)
+	g.require.NoError(err)
+	defer headSub.Unsubscribe()
+
+	var lastActiveBlock uint64
+	for {
+		if untilGameEnds && g.Status(ctx) != StatusInProgress {
+			break
+		}
+		select {
+		case head := <-headCh:
+			if lastActiveBlock == 0 {
+				lastActiveBlock = head.Number.Uint64()
+				continue
+			} else if lastActiveBlock+uint64(numInactiveBlocks) < head.Number.Uint64() {
+				return
+			}
+			block, err := g.client.BlockByNumber(ctx, head.Number)
+			g.require.NoError(err)
+			numActions := 0
+			for _, tx := range block.Transactions() {
+				if tx.To().Hex() == g.addr.Hex() {
+					numActions++
+				}
+			}
+			if numActions != 0 {
+				g.t.Logf("Game %v has %v actions in block %d. Resetting inactivity timeout", g.addr, numActions, block.NumberU64())
+				lastActiveBlock = head.Number.Uint64()
+			}
+		case err := <-headSub.Err():
+			g.require.NoError(err)
+		case <-ctx.Done():
+			g.require.Fail("Context canceled", ctx.Err())
+		}
+	}
+}
+
 // Mover is a function that either attacks or defends the claim at parentClaimIdx
 type Mover func(parentClaimIdx int64)
 
@@ -239,6 +292,21 @@ func (g *FaultGameHelper) ChallengeRootClaim(ctx context.Context, performMove Mo
 	attemptStep(maxDepth)
 }
 
+func (g *FaultGameHelper) WaitForNewClaim(ctx context.Context, checkPoint int64) (int64, error) {
+	timedCtx, cancel := context.WithTimeout(ctx, 2*time.Minute)
+	defer cancel()
+	var newClaimLen int64
+	err := wait.For(timedCtx, time.Second, func() (bool, error) {
+		actual, err := g.game.ClaimDataLen(&bind.CallOpts{Context: ctx})
+		if err != nil {
+			return false, err
+		}
+		newClaimLen = actual.Int64()
+		return actual.Cmp(big.NewInt(checkPoint)) > 0, nil
+	})
+	return newClaimLen, err
+}
+
 func (g *FaultGameHelper) Attack(ctx context.Context, claimIdx int64, claim common.Hash) {
 	tx, err := g.game.Attack(g.opts, big.NewInt(claimIdx), claim)
 	g.require.NoError(err, "Attack transaction did not send")
@@ -266,6 +334,33 @@ func (g *FaultGameHelper) StepFails(claimIdx int64, isAttack bool, stateData []b
 	g.require.Equal("0xfb4e40dd", errData.ErrorData(), "Revert reason should be abi encoded ValidStep()")
 }
 
+// ResolveClaim resolves a single subgame
+func (g *FaultGameHelper) ResolveClaim(ctx context.Context, claimIdx int64) {
+	tx, err := g.game.ResolveClaim(g.opts, big.NewInt(claimIdx))
+	g.require.NoError(err, "ResolveClaim transaction did not send")
+	_, err = wait.ForReceiptOK(ctx, g.client, tx.Hash())
+	g.require.NoError(err, "ResolveClaim transaction was not OK")
+}
+
+// ResolveAllClaims resolves all subgames
+// This function does not resolve the game. That's the responsibility of challengers
+func (g *FaultGameHelper) ResolveAllClaims(ctx context.Context) {
+	loader := fault.NewLoader(g.game)
+	claims, err := loader.FetchClaims(ctx)
+	g.require.NoError(err, "Failed to fetch claims")
+	subgames := make(map[int]bool)
+	for i := len(claims) - 1; i > 0; i-- {
+		subgames[claims[i].ParentContractIndex] = true
+		// Subgames containing only one node are implicitly resolved
+		// i.e. uncountered and claims at MAX_DEPTH
+		if !subgames[i] {
+			continue
+		}
+		g.ResolveClaim(ctx, int64(i))
+	}
+	g.ResolveClaim(ctx, 0)
+}
+
 func (g *FaultGameHelper) gameData(ctx context.Context) string {
 	opts := &bind.CallOpts{Context: ctx}
 	maxDepth := int(g.MaxDepth(ctx))
@@ -277,8 +372,8 @@ func (g *FaultGameHelper) gameData(ctx context.Context) string {
 		g.require.NoErrorf(err, "Fetch claim %v", i)
 
 		pos := types.NewPositionFromGIndex(claim.Position.Uint64())
-		info = info + fmt.Sprintf("%v - Position: %v, Depth: %v, IndexAtDepth: %v Trace Index: %v, Value: %v, Countered: %v\n",
-			i, claim.Position.Int64(), pos.Depth(), pos.IndexAtDepth(), pos.TraceIndex(maxDepth), common.Hash(claim.Claim).Hex(), claim.Countered)
+		info = info + fmt.Sprintf("%v - Position: %v, Depth: %v, IndexAtDepth: %v Trace Index: %v, Value: %v, Countered: %v, ParentIndex: %v\n",
+			i, claim.Position.Int64(), pos.Depth(), pos.IndexAtDepth(), pos.TraceIndex(maxDepth), common.Hash(claim.Claim).Hex(), claim.Countered, claim.ParentIndex)
 	}
 	status, err := g.game.Status(opts)
 	g.require.NoError(err, "Load game status")
@@ -288,3 +383,106 @@ func (g *FaultGameHelper) gameData(ctx context.Context) string {
 func (g *FaultGameHelper) LogGameData(ctx context.Context) {
 	g.t.Log(g.gameData(ctx))
 }
+
+type dishonestClaim struct {
+	ParentIndex int64
+	IsAttack    bool
+	Valid       bool
+}
+type DishonestHelper struct {
+	*FaultGameHelper
+	*HonestHelper
+	claims   map[dishonestClaim]bool
+	defender bool
+}
+
+func NewDishonestHelper(g *FaultGameHelper, correctTrace *HonestHelper, defender bool) *DishonestHelper {
+	return &DishonestHelper{g, correctTrace, make(map[dishonestClaim]bool), defender}
+}
+
+func (t *DishonestHelper) Attack(ctx context.Context, claimIndex int64) {
+	c := dishonestClaim{claimIndex, true, false}
+	if t.claims[c] {
+		return
+	}
+	t.claims[c] = true
+	t.FaultGameHelper.Attack(ctx, claimIndex, common.Hash{byte(claimIndex)})
+}
+
+func (t *DishonestHelper) Defend(ctx context.Context, claimIndex int64) {
+	c := dishonestClaim{claimIndex, false, false}
+	if t.claims[c] {
+		return
+	}
+	t.claims[c] = true
+	t.FaultGameHelper.Defend(ctx, claimIndex, common.Hash{byte(claimIndex)})
+}
+
+func (t *DishonestHelper) AttackCorrect(ctx context.Context, claimIndex int64) {
+	c := dishonestClaim{claimIndex, true, true}
+	if t.claims[c] {
+		return
+	}
+	t.claims[c] = true
+	t.HonestHelper.Attack(ctx, claimIndex)
+}
+
+func (t *DishonestHelper) DefendCorrect(ctx context.Context, claimIndex int64) {
+	c := dishonestClaim{claimIndex, false, true}
+	if t.claims[c] {
+		return
+	}
+	t.claims[c] = true
+	t.HonestHelper.Defend(ctx, claimIndex)
+}
+
+// ExhaustDishonestClaims makes all possible significant moves (mod honest challenger's) in a game.
+// It is very inefficient and should NOT be used on games with large depths
+func (d *DishonestHelper) ExhaustDishonestClaims(ctx context.Context) {
+	depth := d.MaxDepth(ctx)
+
+	move := func(claimIndex int64, claimData ContractClaim) {
+		// dishonest level, valid attack
+		// dishonest level, invalid attack
+		// dishonest level, valid defense
+		// dishonest level, invalid defense
+		// honest level, invalid attack
+		// honest level, invalid defense
+
+		pos := types.NewPositionFromGIndex(claimData.Position.Uint64())
+		if int64(pos.Depth()) == depth {
+			return
+		}
+
+		d.LogGameData(ctx)
+		d.FaultGameHelper.t.Logf("Dishonest moves against claimIndex %d", claimIndex)
+		agreeWithLevel := d.defender == (pos.Depth()%2 == 0)
+		if !agreeWithLevel {
+			d.AttackCorrect(ctx, claimIndex)
+			if claimIndex != 0 {
+				d.DefendCorrect(ctx, claimIndex)
+			}
+		}
+		d.Attack(ctx, claimIndex)
+		if claimIndex != 0 {
+			d.Defend(ctx, claimIndex)
+		}
+	}
+
+	var numClaimsSeen int64
+	for {
+		newCount, err := d.WaitForNewClaim(ctx, numClaimsSeen)
+		if errors.Is(err, context.DeadlineExceeded) {
+			// we assume that the honest challenger has stopped responding
+			// There's nothing to respond to.
+			break
+		}
+		d.FaultGameHelper.require.NoError(err)
+
+		for i := numClaimsSeen; i < newCount; i++ {
+			claimData := d.getClaim(ctx, numClaimsSeen)
+			move(numClaimsSeen, claimData)
+			numClaimsSeen++
+		}
+	}
+}

op-e2e/faultproof_test.go

@@ -3,7 +3,9 @@ package op_e2e
 import (
 	"context"
 	"testing"
+	"time"
 
+	"github.com/ethereum-optimism/optimism/op-challenger/game/fault/types"
 	"github.com/ethereum-optimism/optimism/op-e2e/e2eutils/challenger"
 	"github.com/ethereum-optimism/optimism/op-e2e/e2eutils/disputegame"
 	l2oo2 "github.com/ethereum-optimism/optimism/op-e2e/e2eutils/l2oo"
@@ -62,8 +64,12 @@ func TestMultipleCannonGames(t *testing.T) {
 	sys.TimeTravelClock.AdvanceTime(gameDuration)
 	require.NoError(t, wait.ForNextBlock(ctx, l1Client))
 
-	game1.WaitForGameStatus(ctx, disputegame.StatusChallengerWins)
-	game2.WaitForGameStatus(ctx, disputegame.StatusChallengerWins)
+	game1.WaitForInactivity(ctx, 10, true)
+	game2.WaitForInactivity(ctx, 10, true)
+	game1.LogGameData(ctx)
+	game2.LogGameData(ctx)
+	require.EqualValues(t, disputegame.StatusChallengerWins, game1.Status(ctx))
+	require.EqualValues(t, disputegame.StatusChallengerWins, game2.Status(ctx))
 
 	// Check that the game directories are removed
 	challenger.WaitForGameDataDeletion(ctx, game1, game2)
@@ -168,11 +174,72 @@ func TestChallengerCompleteDisputeGame(t *testing.T) {
 			sys.TimeTravelClock.AdvanceTime(gameDuration)
 			require.NoError(t, wait.ForNextBlock(ctx, l1Client))
 
-			game.WaitForGameStatus(ctx, test.expectedResult)
+			game.WaitForInactivity(ctx, 10, true)
+			game.LogGameData(ctx)
+			require.EqualValues(t, test.expectedResult, game.Status(ctx))
 		})
 	}
 }
 
+func TestChallengerCompleteExhaustiveDisputeGame(t *testing.T) {
+	InitParallel(t)
+
+	testCase := func(t *testing.T, isRootCorrect bool) {
+		ctx := context.Background()
+		sys, l1Client := startFaultDisputeSystem(t)
+		t.Cleanup(sys.Close)
+
+		disputeGameFactory := disputegame.NewFactoryHelper(t, ctx, sys.cfg.L1Deployments, l1Client)
+		rootClaimedAlphabet := disputegame.CorrectAlphabet
+		if !isRootCorrect {
+			rootClaimedAlphabet = "abcdexyz"
+		}
+		game := disputeGameFactory.StartAlphabetGame(ctx, rootClaimedAlphabet)
+		require.NotNil(t, game)
+		gameDuration := game.GameDuration(ctx)
+
+		// Start honest challenger
+		game.StartChallenger(ctx, sys.NodeEndpoint("l1"), "Challenger",
+			challenger.WithAgreeProposedOutput(!isRootCorrect),
+			challenger.WithAlphabet(disputegame.CorrectAlphabet),
+			challenger.WithPrivKey(sys.cfg.Secrets.Alice),
+			// Ensures the challenger responds to all claims before test timeout
+			challenger.WithPollInterval(time.Millisecond*400),
+		)
+
+		// Start dishonest challenger
+		correctTrace := game.CreateHonestActor(ctx, disputegame.CorrectAlphabet, 4)
+		dishonestHelper := disputegame.NewDishonestHelper(&game.FaultGameHelper, correctTrace, !isRootCorrect)
+		dishonestHelper.ExhaustDishonestClaims(ctx)
+
+		// Wait until we've reached max depth before checking for inactivity
+		game.WaitForClaimAtDepth(ctx, int(game.MaxDepth(ctx)))
+
+		// Wait for 4 blocks of no challenger responses. The challenger may still be stepping on invalid claims at max depth
+		game.WaitForInactivity(ctx, 4, false)
+
+		sys.TimeTravelClock.AdvanceTime(gameDuration)
+		require.NoError(t, wait.ForNextBlock(ctx, l1Client))
+
+		expectedStatus := disputegame.StatusChallengerWins
+		if isRootCorrect {
+			expectedStatus = disputegame.StatusDefenderWins
+		}
+		game.WaitForInactivity(ctx, 10, true)
+		game.LogGameData(ctx)
+		require.EqualValues(t, expectedStatus, game.Status(ctx))
+	}
+
+	t.Run("RootCorrect", func(t *testing.T) {
+		InitParallel(t)
+		testCase(t, true)
+	})
+	t.Run("RootIncorrect", func(t *testing.T) {
+		InitParallel(t)
+		testCase(t, false)
+	})
+}
+
 func TestCannonDisputeGame(t *testing.T) {
 	InitParallel(t)
 
@@ -217,8 +284,9 @@ func TestCannonDisputeGame(t *testing.T) {
 			sys.TimeTravelClock.AdvanceTime(game.GameDuration(ctx))
 			require.NoError(t, wait.ForNextBlock(ctx, l1Client))
 
-			game.WaitForGameStatus(ctx, disputegame.StatusChallengerWins)
+			game.WaitForInactivity(ctx, 10, true)
 			game.LogGameData(ctx)
+			require.EqualValues(t, disputegame.StatusChallengerWins, game.Status(ctx))
 		})
 	}
 }
@@ -260,8 +328,9 @@ func TestCannonDefendStep(t *testing.T) {
 	sys.TimeTravelClock.AdvanceTime(game.GameDuration(ctx))
 	require.NoError(t, wait.ForNextBlock(ctx, l1Client))
 
-	game.WaitForGameStatus(ctx, disputegame.StatusChallengerWins)
+	game.WaitForInactivity(ctx, 10, true)
 	game.LogGameData(ctx)
+	require.EqualValues(t, disputegame.StatusChallengerWins, game.Status(ctx))
 }
 
 func TestCannonProposedOutputRootInvalid(t *testing.T) {
@@ -335,14 +404,14 @@ func TestCannonProposedOutputRootInvalid(t *testing.T) {
 			sys.TimeTravelClock.AdvanceTime(game.GameDuration(ctx))
 			require.NoError(t, wait.ForNextBlock(ctx, l1Client))
 
-			game.WaitForGameStatus(ctx, disputegame.StatusDefenderWins)
+			game.WaitForInactivity(ctx, 10, true)
 			game.LogGameData(ctx)
+			require.EqualValues(t, disputegame.StatusDefenderWins, game.Status(ctx))
 		})
 	}
 }
 
 func TestCannonPoisonedPostState(t *testing.T) {
-	t.Skip("Known failure case")
 	InitParallel(t)
 
 	ctx := context.Background()
@@ -365,9 +434,12 @@ func TestCannonPoisonedPostState(t *testing.T) {
 	// Honest defense at "dishonest" level
 	correctTrace.Defend(ctx, 1)
 
-	// Dishonest attack at "honest" level - honest move would be to defend
+	// Dishonest attack at "honest" level - honest move would be to ignore
 	game.Attack(ctx, 2, common.Hash{0x03, 0xaa})
 
+	// Honest attack at "dishonest" level - honest move would be to ignore
+	correctTrace.Attack(ctx, 3)
+
 	// Start the honest challenger
 	game.StartChallenger(ctx, sys.RollupConfig, sys.L2GenesisCfg, l1Endpoint, l2Endpoint, "Honest",
 		// Agree with the proposed output, so disagree with the root claim
@@ -376,29 +448,40 @@ func TestCannonPoisonedPostState(t *testing.T) {
 	)
 
 	// Start dishonest challenger that posts correct claims
-	game.StartChallenger(ctx, sys.RollupConfig, sys.L2GenesisCfg, l1Endpoint, l2Endpoint, "DishonestCorrect",
-		// Disagree with the proposed output, so agree with the root claim
-		challenger.WithAgreeProposedOutput(false),
-		challenger.WithPrivKey(sys.cfg.Secrets.Mallory),
-	)
-
-	// Give the challengers time to progress down the full game depth
-	depth := game.MaxDepth(ctx)
-	for i := 3; i <= int(depth); i++ {
-		game.WaitForClaimAtDepth(ctx, i)
-		game.LogGameData(ctx)
-	}
+	// It participates in the subgame root the honest claim index 4
+	func() {
+		claimCount := int64(5)
+		depth := game.MaxDepth(ctx)
+		for {
+			game.LogGameData(ctx)
+			claimCount++
+			// Wait for the challenger to counter
+			game.WaitForClaimCount(ctx, claimCount)
+
+			// Respond with our own move
+			correctTrace.Defend(ctx, claimCount-1)
+			claimCount++
+			game.WaitForClaimCount(ctx, claimCount)
+
+			// Defender moves last. If we're at max depth, then we're done
+			dishonestClaim := game.GetClaimUnsafe(ctx, claimCount-1)
+			pos := types.NewPositionFromGIndex(dishonestClaim.Position.Uint64())
+			if int64(pos.Depth()) == depth {
+				break
+			}
+		}
+	}()
 
-	// Wait for all the leaf nodes to be countered
-	// Wait for the challengers to drive the game down to the leaf node which should be countered
-	game.WaitForAllClaimsCountered(ctx)
+	// Wait for the challenger to drive the subgame at 4 to the leaf node, which should be countered
+	game.WaitForClaimAtMaxDepth(ctx, true)
 
 	// Time travel past when the game will be resolvable.
 	sys.TimeTravelClock.AdvanceTime(game.GameDuration(ctx))
 	require.NoError(t, wait.ForNextBlock(ctx, l1Client))
 
-	game.WaitForGameStatus(ctx, disputegame.StatusChallengerWins)
+	game.WaitForInactivity(ctx, 10, true)
 	game.LogGameData(ctx)
+	require.EqualValues(t, disputegame.StatusChallengerWins, game.Status(ctx))
 }
 
 // setupDisputeGameForInvalidOutputRoot sets up an L2 chain with at least one valid output root followed by an invalid output root.
@@ -470,8 +553,9 @@ func TestCannonChallengeWithCorrectRoot(t *testing.T) {
 	sys.TimeTravelClock.AdvanceTime(game.GameDuration(ctx))
 	require.NoError(t, wait.ForNextBlock(ctx, l1Client))
 
-	game.WaitForGameStatus(ctx, disputegame.StatusChallengerWins)
+	game.WaitForInactivity(ctx, 10, true)
 	game.LogGameData(ctx)
+	require.EqualValues(t, disputegame.StatusChallengerWins, game.Status(ctx))
 }
 
 func startFaultDisputeSystem(t *testing.T) (*System, *ethclient.Client) {

packages/contracts-bedrock/.gas-snapshot

@@ -91,39 +91,45 @@ FaucetTest:test_nonAdmin_drip_fails() (gas: 262520)
 FaucetTest:test_receive_succeeds() (gas: 17401)
 FaucetTest:test_withdraw_nonAdmin_reverts() (gas: 13145)
 FaucetTest:test_withdraw_succeeds() (gas: 78359)
-FaultDisputeGame_ResolvesCorrectly_CorrectRoot1:test_resolvesCorrectly_succeeds() (gas: 499197)
-FaultDisputeGame_ResolvesCorrectly_CorrectRoot2:test_resolvesCorrectly_succeeds() (gas: 506057)
-FaultDisputeGame_ResolvesCorrectly_CorrectRoot3:test_resolvesCorrectly_succeeds() (gas: 502738)
-FaultDisputeGame_ResolvesCorrectly_CorrectRoot4:test_resolvesCorrectly_succeeds() (gas: 505955)
-FaultDisputeGame_ResolvesCorrectly_CorrectRoot5:test_resolvesCorrectly_succeeds() (gas: 505224)
-FaultDisputeGame_ResolvesCorrectly_IncorrectRoot1:test_resolvesCorrectly_succeeds() (gas: 497962)
-FaultDisputeGame_ResolvesCorrectly_IncorrectRoot2:test_resolvesCorrectly_succeeds() (gas: 504822)
-FaultDisputeGame_ResolvesCorrectly_IncorrectRoot3:test_resolvesCorrectly_succeeds() (gas: 501503)
-FaultDisputeGame_ResolvesCorrectly_IncorrectRoot4:test_resolvesCorrectly_succeeds() (gas: 502720)
-FaultDisputeGame_ResolvesCorrectly_IncorrectRoot5:test_resolvesCorrectly_succeeds() (gas: 501989)
-FaultDisputeGame_Test:test_addLocalData_static_succeeds() (gas: 640504)
+FaultDisputeGame_ResolvesCorrectly_CorrectRoot1:test_resolvesCorrectly_succeeds() (gas: 660411)
+FaultDisputeGame_ResolvesCorrectly_CorrectRoot2:test_resolvesCorrectly_succeeds() (gas: 667293)
+FaultDisputeGame_ResolvesCorrectly_CorrectRoot3:test_resolvesCorrectly_succeeds() (gas: 663974)
+FaultDisputeGame_ResolvesCorrectly_CorrectRoot4:test_resolvesCorrectly_succeeds() (gas: 667169)
+FaultDisputeGame_ResolvesCorrectly_CorrectRoot5:test_resolvesCorrectly_succeeds() (gas: 666460)
+FaultDisputeGame_ResolvesCorrectly_IncorrectRoot1:test_resolvesCorrectly_succeeds() (gas: 653092)
+FaultDisputeGame_ResolvesCorrectly_IncorrectRoot2:test_resolvesCorrectly_succeeds() (gas: 658598)
+FaultDisputeGame_ResolvesCorrectly_IncorrectRoot3:test_resolvesCorrectly_succeeds() (gas: 655943)
+FaultDisputeGame_ResolvesCorrectly_IncorrectRoot4:test_resolvesCorrectly_succeeds() (gas: 656899)
+FaultDisputeGame_ResolvesCorrectly_IncorrectRoot5:test_resolvesCorrectly_succeeds() (gas: 656332)
+FaultDisputeGame_Test:test_addLocalData_static_succeeds() (gas: 640567)
 FaultDisputeGame_Test:test_createdAt_succeeds() (gas: 10342)
-FaultDisputeGame_Test:test_extraData_succeeds() (gas: 32377)
-FaultDisputeGame_Test:test_gameData_succeeds() (gas: 32804)
-FaultDisputeGame_Test:test_gameType_succeeds() (gas: 8309)
-FaultDisputeGame_Test:test_initialize_correctData_succeeds() (gas: 57628)
-FaultDisputeGame_Test:test_initialize_firstOutput_reverts() (gas: 210629)
-FaultDisputeGame_Test:test_initialize_l1HeadTooOld_reverts() (gas: 228390)
-FaultDisputeGame_Test:test_move_clockCorrectness_succeeds() (gas: 415971)
-FaultDisputeGame_Test:test_move_clockTimeExceeded_reverts() (gas: 23197)
-FaultDisputeGame_Test:test_move_defendRoot_reverts() (gas: 13344)
-FaultDisputeGame_Test:test_move_duplicateClaim_reverts() (gas: 102898)
-FaultDisputeGame_Test:test_move_gameDepthExceeded_reverts() (gas: 407913)
+FaultDisputeGame_Test:test_extraData_succeeds() (gas: 32355)
+FaultDisputeGame_Test:test_gameData_succeeds() (gas: 32782)
+FaultDisputeGame_Test:test_gameType_succeeds() (gas: 8265)
+FaultDisputeGame_Test:test_initialize_correctData_succeeds() (gas: 57739)
+FaultDisputeGame_Test:test_initialize_firstOutput_reverts() (gas: 210563)
+FaultDisputeGame_Test:test_initialize_l1HeadTooOld_reverts() (gas: 228368)
+FaultDisputeGame_Test:test_move_clockCorrectness_succeeds() (gas: 594268)
+FaultDisputeGame_Test:test_move_clockTimeExceeded_reverts() (gas: 23175)
+FaultDisputeGame_Test:test_move_defendRoot_reverts() (gas: 13366)
+FaultDisputeGame_Test:test_move_duplicateClaim_reverts() (gas: 147389)
+FaultDisputeGame_Test:test_move_duplicateClaimsDifferentSubgames_succeeds() (gas: 556885)
+FaultDisputeGame_Test:test_move_gameDepthExceeded_reverts() (gas: 585897)
 FaultDisputeGame_Test:test_move_gameNotInProgress_reverts() (gas: 11002)
-FaultDisputeGame_Test:test_move_nonExistentParent_reverts() (gas: 24710)
-FaultDisputeGame_Test:test_move_simpleAttack_succeeds() (gas: 107384)
-FaultDisputeGame_Test:test_resolve_challengeContested_succeeds() (gas: 224949)
-FaultDisputeGame_Test:test_resolve_notInProgress_reverts() (gas: 9686)
-FaultDisputeGame_Test:test_resolve_rootContested_succeeds() (gas: 109879)
-FaultDisputeGame_Test:test_resolve_rootUncontestedClockNotExpired_succeeds() (gas: 21421)
-FaultDisputeGame_Test:test_resolve_rootUncontested_succeeds() (gas: 27279)
-FaultDisputeGame_Test:test_resolve_teamDeathmatch_succeeds() (gas: 395658)
-FaultDisputeGame_Test:test_rootClaim_succeeds() (gas: 8276)
+FaultDisputeGame_Test:test_move_nonExistentParent_reverts() (gas: 24666)
+FaultDisputeGame_Test:test_move_simpleAttack_succeeds() (gas: 151959)
+FaultDisputeGame_Test:test_resolve_challengeContested_succeeds() (gas: 269413)
+FaultDisputeGame_Test:test_resolve_claimAlreadyResolved_reverts() (gas: 272356)
+FaultDisputeGame_Test:test_resolve_claimAtMaxDepthAlreadyResolved_reverts() (gas: 586672)
+FaultDisputeGame_Test:test_resolve_notInProgress_reverts() (gas: 9732)
+FaultDisputeGame_Test:test_resolve_outOfOrderResolution_reverts() (gas: 309037)
+FaultDisputeGame_Test:test_resolve_rootContested_succeeds() (gas: 139044)
+FaultDisputeGame_Test:test_resolve_rootUncontestedButUnresolved_reverts() (gas: 15883)
+FaultDisputeGame_Test:test_resolve_rootUncontestedClockNotExpired_succeeds() (gas: 18406)
+FaultDisputeGame_Test:test_resolve_rootUncontested_succeeds() (gas: 51409)
+FaultDisputeGame_Test:test_resolve_stepReached_succeeds() (gas: 498476)
+FaultDisputeGame_Test:test_resolve_teamDeathmatch_succeeds() (gas: 443373)
+FaultDisputeGame_Test:test_rootClaim_succeeds() (gas: 8232)
 FeeVault_Test:test_constructor_succeeds() (gas: 18185)
 GasBenchMark_L1CrossDomainMessenger:test_sendMessage_benchmark_0() (gas: 354421)
 GasBenchMark_L1CrossDomainMessenger:test_sendMessage_benchmark_1() (gas: 2952628)

packages/contracts-bedrock/semver-lock.json

@@ -18,7 +18,7 @@
   "src/L2/L2StandardBridge.sol": "0xfe01bcb1ddc947b9b8a7093d0971854b9fa8d49da5bd933a3dd106167907f882",
   "src/L2/L2ToL1MessagePasser.sol": "0xafc710b4d320ef450586d96a61cbd58cac814cb3b0c4fdc280eace3efdcdf321",
   "src/L2/SequencerFeeVault.sol": "0xc2f733c1128d06ad60bf1e1d98c8f684a4825b11875ccdf2376ede33f5aad4e6",
-  "src/dispute/FaultDisputeGame.sol": "0x7b8462c29d003e96a73491c644001e1a9034bcc45c5be2a7bac3caf80d521635",
+  "src/dispute/FaultDisputeGame.sol": "0x76e7c16431faa32e2074e6abdfe3e86f5ec90b4ac8a6b662edba8c3ce791ad80",
   "src/legacy/DeployerWhitelist.sol": "0xf2129ec3da75307ba8e21bc943c332bb04704642e6e263149b5c8ee92dbcb7a8",
   "src/legacy/L1BlockNumber.sol": "0x30aae1fc85103476af0226b6e98c71c01feebbdc35d93401390b1ad438a37be6",
   "src/legacy/LegacyMessagePasser.sol": "0x5c08b0a663cc49d30e4e38540f6aefab19ef287c3ecd31c8d8c3decd5f5bd497",

packages/contracts-bedrock/src/dispute/FaultDisputeGame.sol

@@ -75,6 +75,12 @@ contract FaultDisputeGame is IFaultDisputeGame, Clone, Semver {
     /// @notice An internal mapping to allow for constant-time lookups of existing claims.
     mapping(ClaimHash => bool) internal claims;
 
+    /// @notice An internal mapping of subgames rooted at a claim index to other claim indices in the subgame.
+    mapping(uint256 => uint256[]) internal subgames;
+
+    /// @notice Indicates whether the subgame rooted at the root claim has been resolved.
+    bool internal subgameAtRootResolved;
+
     /// @param _gameType The type ID of the game.
     /// @param _absolutePrestate The absolute prestate of the instruction trace.
     /// @param _maxGameDepth The maximum depth of bisection.
@@ -232,9 +238,10 @@ contract FaultDisputeGame is IFaultDisputeGame, Clone, Semver {
         // Construct the next clock with the new duration and the current block timestamp.
         Clock nextClock = LibClock.wrap(nextDuration, Timestamp.wrap(uint64(block.timestamp)));
 
-        // INVARIANT: A claim may only exist at a given position once. Multiple claims may exist
-        //            at the same position, however they must have different values.
-        ClaimHash claimHash = _claim.hashClaimPos(nextPosition);
+        // INVARIANT: There cannot be multiple identical claims with identical moves on the same challengeIndex. Multiple
+        // claims
+        //            at the same position may dispute the same challengeIndex. However, the must have different values.
+        ClaimHash claimHash = _claim.hashClaimPos(nextPosition, _challengeIndex);
         if (claims[claimHash]) revert ClaimAlreadyExists();
         claims[claimHash] = true;
 
@@ -252,6 +259,9 @@ contract FaultDisputeGame is IFaultDisputeGame, Clone, Semver {
         // Set the parent claim as countered.
         claimData[_challengeIndex].countered = true;
 
+        // Update the subgame rooted at the parent claim.
+        subgames[_challengeIndex].push(claimData.length - 1);
+
         // Emit the appropriate event for the attack or defense.
         emit Move(_challengeIndex, _claim, msg.sender);
     }
@@ -348,67 +358,64 @@ contract FaultDisputeGame is IFaultDisputeGame, Clone, Semver {
         // INVARIANT: Resolution cannot occur unless the game is currently in progress.
         if (status != GameStatus.IN_PROGRESS) revert GameNotInProgress();
 
-        // Search for the left-most dangling non-bottom node
-        // The most recent claim is always a dangling, non-bottom node so we start with that
-        uint256 leftMostIndex = claimData.length - 1;
-        uint256 leftMostTraceIndex = type(uint128).max;
-        for (uint256 i = leftMostIndex; i < type(uint64).max;) {
-            // Fetch the claim at the current index.
-            ClaimData storage claim = claimData[i];
-
-            // Decrement the loop counter; If it underflows, we've reached the root
-            // claim and can stop searching.
-            unchecked {
-                --i;
-            }
+        // INVARIANT: Resolution cannot occur unless the absolute root subgame has been resolved.
+        if (!subgameAtRootResolved) revert OutOfOrderResolution();
 
-            // INVARIANT: A claim can never be considered as the leftMostIndex or leftMostTraceIndex
-            //            if it has been countered.
-            if (claim.countered) continue;
-
-            // If the claim is a dangling node, we can check if it is the left-most
-            // dangling node we've come across so far. If it is, we can update the
-            // left-most trace index.
-            uint256 traceIndex = claim.position.traceIndex(MAX_GAME_DEPTH);
-            if (traceIndex < leftMostTraceIndex) {
-                leftMostTraceIndex = traceIndex;
-                unchecked {
-                    leftMostIndex = i + 1;
-                }
-            }
-        }
+        status_ = claimData[0].countered ? GameStatus.CHALLENGER_WINS : GameStatus.DEFENDER_WINS;
+        emit Resolved(status = status_);
+    }
 
-        // Create a reference to the left most uncontested claim and its parent.
-        ClaimData storage leftMostUncontested = claimData[leftMostIndex];
+    /// @inheritdoc IFaultDisputeGame
+    function resolveClaim(uint256 _claimIndex) external payable {
+        // INVARIANT: Resolution cannot occur unless the game is currently in progress.
+        if (status != GameStatus.IN_PROGRESS) revert GameNotInProgress();
 
-        // INVARIANT: The game may never be resolved unless the clock of the left-most uncontested
-        //            claim's parent has expired. If the left-most uncontested claim is the root
-        //            claim, it is uncountered, and we check if 3.5 days has passed since its
-        //            creation.
-        uint256 parentIndex = leftMostUncontested.parentIndex;
-        Clock opposingClock = parentIndex == type(uint32).max ? leftMostUncontested.clock : claimData[parentIndex].clock;
+        ClaimData storage parent = claimData[_claimIndex];
+
+        // INVARIANT: Cannot resolve a subgame unless the clock of its root has expired
         if (
-            Duration.unwrap(opposingClock.duration()) + (block.timestamp - Timestamp.unwrap(opposingClock.timestamp()))
+            Duration.unwrap(parent.clock.duration()) + (block.timestamp - Timestamp.unwrap(parent.clock.timestamp()))
                 <= Duration.unwrap(GAME_DURATION) >> 1
         ) {
             revert ClockNotExpired();
         }
 
-        // If the left-most dangling node is at an even depth, the defender wins.
-        // Otherwise, the challenger wins and the root claim is deemed invalid.
-        if (
-            leftMostUncontested
-                .position
-                // slither-disable-next-line weak-prng
-                .depth() % 2 == 0 && leftMostTraceIndex != type(uint128).max
-        ) {
-            status_ = GameStatus.DEFENDER_WINS;
-        } else {
-            status_ = GameStatus.CHALLENGER_WINS;
+        uint256[] storage challengeIndices = subgames[_claimIndex];
+
+        // INVARIANT: Cannot resolve subgames twice
+        // Uncontested claims are resolved implicitly unless they are the root claim
+        if (_claimIndex == 0 && subgameAtRootResolved) revert ClaimAlreadyResolved();
+        if (challengeIndices.length == 0 && _claimIndex != 0) revert ClaimAlreadyResolved();
+
+        // Assume parent is honest until proven otherwise
+        bool countered = false;
+
+        for (uint256 i = 0; i < challengeIndices.length; ++i) {
+            uint256 challengeIndex = challengeIndices[i];
+
+            // INVARIANT: Cannot resolve a subgame containing an unresolved claim
+            if (subgames[challengeIndex].length != 0) revert OutOfOrderResolution();
+
+            ClaimData storage claim = claimData[challengeIndex];
+
+            // Ignore false claims
+            if (!claim.countered) {
+                countered = true;
+                break;
+            }
         }
 
-        // Update the game status
-        emit Resolved(status = status_);
+        // Once a subgame is resolved, we percolate the result up the DAG so subsequent calls to
+        // resolveClaim will not need to traverse this subgame.
+        parent.countered = countered;
+
+        // Resolved subgames have no entries
+        delete subgames[_claimIndex];
+
+        // Indicate the game is ready to be resolved
+        if (_claimIndex == 0) {
+            subgameAtRootResolved = true;
+        }
     }
 
     /// @inheritdoc IDisputeGame

packages/contracts-bedrock/src/dispute/interfaces/IFaultDisputeGame.sol

@@ -73,6 +73,14 @@ interface IFaultDisputeGame is IDisputeGame {
     /// @param _partOffset The offset of the data to post.
     function addLocalData(uint256 _ident, uint256 _partOffset) external;
 
+    /// @notice Resolves the subgame rooted at the given claim index.
+    /// @dev This function must be called bottom-up in the DAG
+    ///      A subgame is a tree of claims that has a maximum depth of 1.
+    ///      A subgame root claims is valid if, and only if, all of its child claims are invalid.
+    ///      At the deepest level in the DAG, a claim is invalid if there's a successful step against it.
+    /// @param _claimIndex The index of the subgame root claim to resolve.
+    function resolveClaim(uint256 _claimIndex) external payable;
+
     /// @notice An L1 block hash that contains the disputed output root, fetched from the
     ///         `BlockOracle` and verified by referencing the timestamp associated with the
     ///         first L2 Output Proposal in the `L2OutputOracle` that contains the disputed

packages/contracts-bedrock/src/dispute/lib/LibHashing.sol

@@ -9,11 +9,20 @@ library LibHashing {
     /// @notice Hashes a claim and a position together.
     /// @param _claim A Claim type.
     /// @param _position The position of `claim`.
-    /// @return claimHash_ A hash of abi.encodePacked(claim, position);
-    function hashClaimPos(Claim _claim, Position _position) internal pure returns (ClaimHash claimHash_) {
+    /// @param _challengeIndex The index of the claim being moved against.
+    /// @return claimHash_ A hash of abi.encodePacked(claim, position|challengeIndex);
+    function hashClaimPos(
+        Claim _claim,
+        Position _position,
+        uint256 _challengeIndex
+    )
+        internal
+        pure
+        returns (ClaimHash claimHash_)
+    {
         assembly {
             mstore(0x00, _claim)
-            mstore(0x20, _position)
+            mstore(0x20, or(shl(128, _position), and(0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF, _challengeIndex)))
             claimHash_ := keccak256(0x00, 0x40)
         }
     }

packages/contracts-bedrock/src/libraries/DisputeErrors.sol

@@ -66,6 +66,12 @@ error L1HeadTooOld();
 /// @notice Thrown when an invalid local identifier is passed to the `addLocalData` function.
 error InvalidLocalIdent();
 
+/// @notice Thrown when resolving claims out of order.
+error OutOfOrderResolution();
+
+/// @notice Thrown when resolving a claim that has already been resolved.
+error ClaimAlreadyResolved();
+
 ////////////////////////////////////////////////////////////////
 //              `AttestationDisputeGame` Errors               //
 ////////////////////////////////////////////////////////////////