Pure rules library with no Orleans or database. Command in, events out. Deterministic RNG stored in GameState. Covers setup with starting vanguard and mulligan, six phases, ride, call, attack, guard, drive check, damage check with triggers, retirement and win at six damage. 8 engine tests, 30 total. Sentinel, boost and card abilities are the next step.
Solution on .NET 10 LTS with rules, content and CLI projects. Content importer pulls stats from the official card list, merges trigger/rarity data, emits three YAML sets (94 cards, 124 printings). Validator checks the grade-0 shield invariant, sentinel shield, parallel printing links, and deck construction limits. 14 tests cover catalog integrity and deck validation.