1 Balance query 2 Debit reduces balance 3 Credit increases balance 4 Full round 5 Rollback restores balance 6 Multi-action round 7 Zero-win round

8 Duplicate debit 9 Duplicate credit 10 Duplicate rollback

11 Insufficient funds 12 Rollback unknown tx 13 Invalid session 14 Credit after rollback

15 Wrong HMAC signature 16 Mismatched body HMAC 17 Tampered body 29 Replay attack

18 Negative debit amount 19 Negative credit amount 20 Zero debit amount 21 Overflow amount 22 SQL injection in playerId 23 XSS in fields 24 Missing required fields 25 Extra unknown fields 26 Wrong Content-Type 27 Concurrent duplicates 28 Credit without debit

30 Very long strings 31 Unicode/emoji 32 Decimal precision 33 Empty playerId 34 Rapid requests

35 Rollback before debit 36 Rollback-debit-credit ordering 37 Concurrent debit and rollback 38 Late debit after confirmed rollback