docs: add gas_costs.md (#404)

book/SUMMARY.md

@@ -27,6 +27,7 @@
   - [Deploy FP Contracts](./fault_proofs/deploy.md)
   - [How to run the FP Proposer](./fault_proofs/proposer.md)
   - [How to run the FP Challenger](./fault_proofs/challenger.md)
+  - [Gas Costs](./fault_proofs/gas_costs.md)
 - [Experimental](./experimental/intro.md)
   - [OptimismPortalV2](./experimental/optimism-portal-v2.md)
 - [FAQ](./faq.md)

book/fault_proofs/gas_costs.md

@@ -0,0 +1,40 @@
+## Gas Costs
+
+For the most accurate gas estimates, always test with your specific use case and conditions.
+
+Here are the typical gas costs for key operations in the fault proof system:
+
+### Game Creation (Propose)
+Creating a new game through the factory costs approximately 330,000 gas. This includes:
+- Factory proxy delegation (~25,000 gas)
+- Game proxy creation (~44,000 gas)
+- Game initialization (~175,000 gas)
+- Event emissions and state updates
+
+### Challenge
+Challenging a game costs approximately 85,000 gas. This includes:
+- State validation checks
+- Updating game status
+- Setting challenge deadline
+- Recording challenger address
+- Event emissions
+
+### Proving
+Proving a game costs approximately 280,000~300,000 gas. This includes:
+- Proof verification
+- State updates
+- Event emissions
+
+### Resolution
+Resolving a game costs approximately 85,000 gas for a standard resolution. This includes:
+- Parent game validation
+- Status checks and updates
+- Bond distribution calculations
+- Event emissions
+
+### Credit Claiming
+Claiming credit (bonds/rewards) costs approximately 85,000 gas. This includes:
+- Game finalization checks
+- Credit balance updates
+- ETH transfers
+- Event emissions