GameInvariants checks card counts, unique instance ids and damage. The CLI stress command runs random legal bot games and fails on the first violation. It exposed a real bug: an optional OnGuard ability that could not be paid (or was declined) reset the step from Guard to None while the battle was still open. OfferAbility now reports Skipped/Paused/Resolved and callers continue only when needed. 1000/1000 games finish with no errors.
Normal units can no longer attack the back row; Wyvern Strike, Tejas attacks the back row of its own column. Demonic Dragon Berserker, Yaksha rides itself from hand when an opponent's rear-guard is retired during the main phase. Match replay: CommandCodec, MatchRecord, MatchRecorder, ReplayRunner and an FNV event hash; a JSON round-trip replays a full bot game bit-for-bit. Three tests; 116 total.
GameEngine.LegalCommands returns every meaningful command for the current phase, pending trigger, ability, order or choice. A random bot plays 50 deterministic games and checks that each player always has 50 cards across zones, instance ids stay unique and damage never exceeds six. Fixes found by the bot: search-to-call no longer loses a card when there is no empty circle (InTransit), a stand trigger with no rear-guards can resolve, unpayable optional abilities no longer stall the order, and legal intents skip impossible retire-self and repeated intercept commands.
New triggers: OnBoostedHit, OnRetireFromRC, OnOpponentRetire, OnGuard; activated abilities from hand and drop zone; superior ride from drop. Cards: Voidmaster, Hagakure, Dreadmaster, Monster Frank, Blightops, Llew, Dragon Knight Aleph, Gancelot hand effect, Deathrex second effect, Brigitte, Bors, Tristan, Starlight Unicorn, Goku, Berserk Dragon, Aermo, Joka, Rakshasa. Four tests; 111 total.
Asura Kaiser reacts to grade 3 Nova Grappler drive checks; Rock the Wall and Redshoe Milly move from the guardian circle to soul; Juggernaut and Brakki return to deck after battle; Lozenge and Battleraizer return at end of turn; Guiding Zombie puts itself into soul and mills three. Four tests; 102 total.
AskUnitMultiChoice asks one target at a time, offers Done once the minimum is met and resolves automatically at the maximum. CardRestriction models cannot-stand/attack/boost/intercept with source, effect id and duration, including UntilOwnerNextStand. Restraint can be overridden by effects. OnAttackHit now fires when the attack hits a rear-guard. Five tests.
StatModifier stores value, source card, effect id and duration (battle / turn / permanent), so a specific effect can be removed without touching others. GrantedAbility lets effects add abilities that are not printed on the card; the engine merges printed and granted abilities. Boost and trigger bonuses now use modifiers. Three tests.
AskHandCardChoice pauses on the hand and returns the chosen card, so abilities can pay discard costs interactively. Knight of Rose, Morgana implemented: on attack, optionally discard a card for +4000 until end of turn. Test covers the full pause chain and the return to the guard step.
Added a command guard while an ability resolves, a continuation mechanism for mid-battle pauses, and TriggerAll for scanning the field. Cards: Demon Eater (soul charge at main phase start), Tyrant Deathrex (+5000 when attacking), Maiden of Libra (Counter Blast 2 and draw on hit). Three tests.
LookTopAndReorder asks top or bottom without revealing the deck. SearchDeckToCall and SearchDeckToRide wrap the search primitive; Alfred searches a Royal Paladin grade 2 or lower and calls it, Cocoa looks at the top card. Five tests.
SearchDeck hides the deck and returns matches only: none -> SearchFailedEvent and shuffle, one -> straight to the effect, several -> PendingChoice. Different arts are separate results, labelled with the printing id. Wired into Conroe, which pays Counter Blast 1 and retires itself. Four tests.
PendingChoice/ChooseCommand let effects ask the player to pick a unit. Added Counter Blast and Soul Blast cost helpers. Blaster Blade implemented for both zones with its CB2 cost and rear-guard target. Activated abilities pay rest-self and discard; Lake Maiden Lien, Gojo and Shout draw a card. Seven tests.
CardScript model with Triggered and Continuous abilities. Check Timing collects triggered abilities, orders them (turn player first, player picks the order via SelectTriggerCommand), and pauses on optional abilities (ResolveAbilityCommand). Continuous effects are recomputed on demand in EffectivePower. Scripts: Barcgal (optional call from soul), Wingal (+4000 when boosting Blaster Blade), Alfred (+2000 per Royal Paladin rear-guard). Six tests.
Grade 0-2 vanguard performs one check, grade 3+ performs two, rear-guards perform none by default. CardInstance.DriveChecksOverride lets effects remove Twin Drive or grant checks to a rear-guard. Added DriveCheckedEvent for the log. Five tests.
MoveCommand(from, to) in the Main phase. Only 0-3 (left) and 2-4 (right) are valid pairs; the center back row has no partner. Rested state stays with the card. Five tests.
InterceptCommand during the guard step. The interceptor leaves its circle, becomes the power reference for the attack and goes to the drop zone at the end of the battle; the original target survives. Grade 1 cannot intercept, back row only with InterceptFromBackRow granted by an effect. Five tests.
GuardCommand takes an optional discard. Sentinel cards have zero shield; paying with a card of the same clan sets Nullified on the battle so power no longer matters. Three tests: paid, unpaid, wrong clan.
Cards of grade 0 and 1 have boost by default (HasBoost); CardInstance.BoostOverride lets an effect grant or remove it at runtime. AttackCommand takes an optional BoosterSlot: the back-row unit in the same column adds its power for that battle only and becomes rested. Four new tests.
Order is now: reveal -> trigger zone -> resolve effects -> hand (drive check) or damage (damage check). Damage is added only after the trigger resolves, so heal compares the pre-damage count. Temporary power/crit are cleared at end of turn instead of end of battle.
Drive check now pauses on a trigger and waits for ResolveTriggerCommand(powerTarget, effectTarget). Power and crit modifiers moved from the battle to the unit and are cleared at the end of the battle. Stand stands the chosen rear-guard; Critical applies +1 crit to the chosen unit. Damage-check triggers still apply only the secondary effect.
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.
MpakobecEx