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Port MTG Engine to Rust for AI TrainingPublic

The user aimed to port a Java-based Magic: The Gathering engine to Rust to enable efficient reinforcement learning AI training with Python integration. Progress included setting up the workspace, implementing core game components like player states and mana pools, developing AI logic with passing tests, and creating a robust ability and effect framework. The project advanced through multiple completed tasks, ensuring the engine's functionality and AI capabilities were thoroughly tested and operational.

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Claude Code

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Claude Opus 4.6

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Feb 13, 6:08 PM

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Request interrupted by user for tool use

Implement the following plan:

Plan: Port XMage to Rust for RL AI Training

Context

XMage is a Java MTG engine that is not thread-safe and doesn't efficiently use CPU at scale. The goal is to port the core game engine, AI player framework, and cards from 4 sets to Rust, with Python bindings via PyO3 for use as an OpenAI Gymnasium RL environment. Only standard 1v1 (two-player duel) is needed.

Card sets to port:

FDN (Foundations, ~730 entries) — curated subset (~150 cards) for core mechanics coverage: counterspells, removal, vanilla creatures, equipment, auras, tokens, basic lands
TLA (Avatar: The Last Airbender, ~392 cards) — full set
TDM (Tarkir: Dragonstorm, ~432 cards) — full set
ECL (Lorwyn Eclipsed, ~227 cards) — full set

Project Structure

Cargo workspace at /mnt/dest-btrfs/home/jc/src/mage/mtg-rl/:

mtg-rl/
  Cargo.toml                    # workspace root
  crates/
    mtg-engine/                 # Core rules engine
    mtg-cards/                  # Card implementations (FDN, TLA, TDM, ECL)
    mtg-ai/                     # AI players + RL interface
    mtg-python/                 # PyO3 bindings (cdylib)
    mtg-tests/                  # Integration test framework + ported JUnit tests

Team Structure (3 teammates)

Teammate 1: `engine` — Core Game Engine

Teammate 2: `ai` — AI Players + PyO3/Gymnasium

Teammate 3: `cards` — Card Implementations for FDN, TLA, TDM, ECL

Phase 1: Foundation (all teams start in parallel)

Engine teammate

Set up Cargo workspace with all 5 crates
constants.rs — All enums (Zone, PhaseStep, CardType, SubType, Layer, Duration, etc.) from Mage/src/main/java/mage/constants/
types.rs — ObjectId, PlayerId (Uuid-based typed wrappers)
mana.rs — Mana struct + arithmetic (port Mage/src/main/java/mage/Mana.java)
counters.rs — Counter types
card.rs — CardData struct (composition-based, replaces CardImpl inheritance)
permanent.rs — Permanent struct (embeds CardData + battlefield state)
player/player.rs — Player struct with life/hand/library/graveyard
player/mana_pool.rs — ManaPool
battlefield.rs, stack.rs — Zone containers
zones.rs — Zone management + zone change logic (port ZonesHandler.java)
state.rs — GameState struct aggregating all zones/effects/triggers
turn.rs — Turn/Phase/Step state machine
game.rs — Game struct shell with new_two_player(), turn loop skeleton

Key design decisions:

Use im crate for persistent HashMap/Vector (cheap clone for AI search)
Use bitflags for keyword abilities (O(1) checks vs Java's hash lookup)
All types Send + Sync — no Rc, RefCell, or raw pointers
UUID-based object references (direct translation from Java)

AI teammate

Define PlayerDecisionMaker trait — the ~15 decision methods from Player.java:
- priority(), choose_target(), choose_use(), select_attackers(), select_blockers(), choose_mode(), assign_damage(), choose_mulligan(), etc.
Define PlayerAction enum (Pass, CastSpell, ActivateAbility, PlayLand)
random_player.rs — Random legal-action player (testing baseline)
evaluator.rs — Port GameStateEvaluator2 scoring (life + permanents + hand)
Design observation encoding (observation.rs) and action space (action.rs)

Critical dependency: AI teammate delivers PlayerDecisionMaker trait by end of Phase 1. Engine integrates it into the game loop.

Cards teammate

registry.rs — CardRegistry with type CardFactory = fn(ObjectId, PlayerId) -> CardData
Set registration files: sets/fdn.rs, sets/tla.rs, sets/tdm.rs, sets/ecl.rs
All basic lands for each set
FDN curated subset first (~150 cards covering core mechanics):
- Counterspells (Cancel, etc.)
- Basic removal (Murder, Doom Blade type)
- Vanilla/keyword creatures across all colors
- Equipment and auras
- Token creators
- Card draw spells
- Combat tricks
All Tier 1 cards from TLA/TDM/ECL — vanilla/keyword-only creatures (~30%)

Critical dependency: Cards teammate needs CardData struct from Engine by end of week 1.

Phase 2: Core Systems

Engine teammate

events.rs — GameEvent enum (600+ types), fire_event, replace_event dispatch
priority.rs — Priority loop (port GameImpl.playPriority)
abilities/ability.rs — Ability trait + common implementations
abilities/activated.rs, triggered.rs, spell.rs, static_ability.rs, mana_ability.rs
effects/continuous.rs — 7-layer effects system (port ContinuousEffects.java):
- Layer 1: Copy → 2: Control → 3: Text → 4: Type → 5: Color → 6: Ability → 7: P/T (with sublayers 7a-7e)
effects/replacement.rs, one_shot.rs, prevention.rs, restriction.rs
combat.rs — Full combat system (port Combat.java — declare attackers/blockers, damage assignment)
watchers/ — Watcher trait + common watchers
filters/ — Filter/Predicate composable system (port StaticFilters.java)
targets/ — Target system (TargetCard, TargetPermanent, TargetPlayer)

AI teammate

heuristic_player.rs — Port ComputerPlayer.java (1,350 lines) — heuristic-based decisions
Start minimax_player.rs — Port ComputerPlayer6.java (1,251 lines) — minimax with alpha-beta + parallel search via rayon
Start gym.rs — Gymnasium env logic (step/reset/observation/action_mask)
mtg-python/src/lib.rs — PyO3 module skeleton with #[pyclass] MtgEnv

Cards teammate

Set-specific keyword mechanics:
- keywords/waterbend.rs — TLA mechanic
- keywords/airbend.rs — TLA mechanic
- keywords/mobilize.rs — TDM mechanic
Port common building-block abilities to mtg-engine:
- Triggers: EntersBattlefieldTriggeredAbility, DiesTriggeredAbility, AttacksTriggeredAbility, DealsCombatDamageToAPlayerTriggeredAbility, BeginningOfEndStepTriggeredAbility, SpellCastControllerTriggeredAbility
- Effects: DestroyTargetEffect, ExileTargetEffect, DamageTargetEffect, DrawCardSourceControllerEffect, GainLifeEffect, BoostTargetEffect, BoostControlledEffect, CreateTokenEffect, CounterTargetEffect, ScryEffect, ExileUntilSourceLeavesEffect
- Costs: TapSourceCost, SacrificeSourceCost, DiscardCost, PayLifeCost
All Tier 2 cards (~35%) — standard ability compositions across all 4 sets
Begin Tier 3 cards (~20%) — modal spells, lords, conditional effects

Phase 3: Integration & Complex Cards

Engine teammate

Complete game loop: full game playable with simple cards end-to-end
State-based actions (SBA) checking
Stack resolution edge cases (fizzle, counter, copy on stack)
Last-known information (LKI) system
Transform/double-faced card support
Aura/equipment attachment system
Performance: profiling, im:: tuning, verify Send + Sync everywhere
Concurrency validation: run parallel games via rayon, establish baseline throughput

AI teammate

Complete minimax player with parallel branch search
Complete PyO3 bindings + Python Gymnasium wrapper (pip install via maturin)
Reward shaping: win/loss (+1/-1), intermediate reward from life differential
Action space: two-phase approach (action type selection, then parameterization) to avoid combinatorial explosion
Observation space: fixed-size tensors (life, mana, permanents, hand, stack, phase, action mask)

Cards teammate

All Tier 3 cards — moderate complexity (modal, lords, multi-ability)
All Tier 4 cards (~15%) — planeswalkers, DFCs, sagas, custom effects
Card-specific unit tests for every complex card

Phase 4: Testing & Polish

Test strategy: Port core + cherry-pick + gap-fill

1. Port ALL existing core engine tests from Mage.Tests/:

Combat tests (12 files) — Mage.Tests/.../test/combat/
Game tests (5 files) — Mage.Tests/.../test/game/
State-based action tests (1 file)
Turn modification tests (2 files)
LKI tests (1 file)

2. Port card-specific tests for our 4 sets:

TDM: 7 existing test files
FDN: 1 existing test file
TLA, ECL: 0 existing tests (write new ones)

3. Cherry-pick card tests from OTHER sets that exercise critical mechanics missing from our sets:

Counterspell interactions (stack mechanics)
Replacement effect ordering
Triggered ability ordering (APNAP)
Copy/clone effects
X spells
Protection/hexproof/ward
Sacrifice-as-cost vs sacrifice-as-effect
"Dies" triggers vs "leaves the battlefield"

4. Write new Rust tests for remaining gaps:

7-layer continuous effects system (each layer individually + interactions)
Mana payment system (generic, colored, conditional, hybrid)
Stack resolution (priority passing, fizzle, counter)
Zone transition edge cases
State-based actions (comprehensive)

5. Fuzz + performance testing:

Random games with crash detection
Establish games/second baseline and profile bottlenecks (optimize iteratively, no fixed target)
Verify the Gymnasium env runs end-to-end (reset → step → observe → repeat)
RL agent training (PPO etc.) deferred to a future phase

Test framework mirrors CardTestPlayerBase API:

rust

Key Design Decisions

Decision	Choice	Why
Object identity	`uuid` crate, typed wrappers	Direct from Java, `Send + Sync`
Inheritance → Rust	Composition + traits	Idiomatic Rust; CardData embeds in Permanent
Card implementations	Factory fns + registry	No class hierarchy; cards are data + behavior
Keywords	`bitflags` u64	O(1) checks, huge perf win over Java HashMap
Game state cloning	`im` crate persistent structures	Near-O(1) clone for AI search branches
Effect layers	Direct port of Java 7-layer system	MTG rule 613 requires exact ordering
Thread safety	All `Send + Sync`, no Rc/RefCell	Entire point of the port
Parallelism	`rayon` for games + AI search	Work-stealing thread pool
Python bindings	PyO3 + maturin	Industry standard Rust-Python interop
RL action space	Two-phase (type + parameterization)	Avoids combinatorial explosion

Critical Source Files (Java → Rust reference)

Mage/src/main/java/mage/game/GameImpl.java (4,270 lines) → mtg-engine/src/game.rs
Mage/src/main/java/mage/game/GameState.java (1,758 lines) → mtg-engine/src/state.rs
Mage/src/main/java/mage/abilities/effects/ContinuousEffects.java (1,427 lines) → mtg-engine/src/effects/continuous.rs
Mage/src/main/java/mage/game/combat/Combat.java (1,956 lines) → mtg-engine/src/combat.rs
Mage/src/main/java/mage/game/permanent/PermanentImpl.java (2,202 lines) → mtg-engine/src/permanent.rs
Mage/src/main/java/mage/abilities/AbilityImpl.java (1,966 lines) → mtg-engine/src/abilities/ability.rs
Mage/src/main/java/mage/players/Player.java (760 lines) → PlayerDecisionMaker trait
Mage.Player.AI.MA/.../ComputerPlayer6.java (1,251 lines) → mtg-ai/src/minimax_player.rs
Mage.Player.AI/.../ComputerPlayer.java (1,350 lines) → mtg-ai/src/heuristic_player.rs
Mage.Sets/src/mage/sets/Foundations.java — FDN set definition (curated subset source)
Mage.Sets/src/mage/sets/AvatarTheLastAirbender.java — TLA set definition
Mage.Sets/src/mage/sets/TarkirDragonstorm.java — TDM set definition
Mage.Sets/src/mage/sets/LorwynEclipsed.java — ECL set definition

If you need specific details from before exiting plan mode (like exact code snippets, error messages, or content you generated), read the full transcript at: /mnt/dest-btrfs/home/jc/.claude/projects/-mnt-dest-btrfs-home-jc-src-mage/60ce8554-7ed5-4f1a-b3ee-e636dd4f7ae0.jsonl

If this plan can be broken down into multiple independent tasks, consider using the TeamCreate tool to create a team and parallelize the work.

This is a massive project. I'll create a team with 3 parallel teammates as the plan specifies. Let me set up the workspace structure first, then create the team and dispatch work.

Used TeamCreate

Now let me create the task list and spawn teammates. First, the tasks:

Used TaskCreate

Now let me create Phase 2 tasks:

Used TaskCreate

Now Phase 3 & 4 tasks:

Used TaskCreate

Now let me set up dependencies between tasks:

Used TaskUpdate

Good. Now let me spawn the 3 teammates. The critical path starts with the engine teammate setting up the workspace (task #1), then all three can work in parallel. Let me start the engine teammate first since tasks #7 (AI) and #10 (cards) depend on its early output, but I'll spawn all three — the AI and cards teammates can start on their unblocked work immediately after workspace exists.

Ran sub-agentCore game engine teammate

Ran sub-agentAI player + PyO3 teammate

Ran sub-agentCard implementations teammate

All 3 teammates are now running in parallel. Here's the team structure:

Team mtg-rl — 3 teammates working in parallel:

Teammate	Role	Starting Tasks
`engine`	Core game engine (mtg-engine)	#1 Workspace → #2 Constants → #3 Types → #4 Card/Permanent → #5 Player/Zones → #6 Game loop
`ai`	AI players + PyO3 (mtg-ai, mtg-python)	#7 PlayerDecisionMaker trait → #8 Random player → #9 Observation space
`cards`	Card implementations (mtg-cards)	#10 Registry → #11 FDN cards → #12 TLA/TDM/ECL Tier 1

26 tasks across 4 phases with dependency tracking. The critical path is:

#1 Workspace → #2 Constants → #3 Types → #4 CardData → #5 State → #6 Game Loop → #13 Events → #14 Abilities → #15 Combat → #23 Full Game
                                                    ↘ #10 Registry → #11 FDN → ...
                 #7 DecisionMaker trait → #8 Random Player → #20 Heuristic → #21 Minimax

I'll monitor progress and coordinate as the teammates work. Let me check their initial status.

Listed

The engine teammate has already claimed and started task #1 (workspace setup). The AI and cards teammates are waiting for their dependencies to unblock. All three are running in the background and will coordinate via messages as they progress.

I'll keep monitoring and step in to help coordinate if needed. The teammates will message me when they hit milestones or need decisions.

<teammate-message teammate_id="engine" color="blue" summary="Workspace setup complete, starting constants"> Task #1 (workspace setup) is complete. All 5 crates compile: mtg-engine, mtg-cards, mtg-ai, mtg-python, mtg-tests. The workspace is at /mnt/dest-btrfs/home/jc/src/mage/mtg-rl/. I'm now working on task #2 (constants.rs). </teammate-message>

Good, workspace is up. Task #7 is now unblocked for the AI teammate. Let me notify them.

Used SendMessage

Both the engine (#2 constants) and AI (#7 PlayerDecisionMaker) teammates are actively working. The cards teammate is waiting for task #4 (CardData struct) to unblock. Progress is on track — the critical path items are being worked in parallel.

<teammate-message teammate_id="engine" color="blue" summary="Task #5 done: player, mana pool, zones, state implemented"> Task #5 complete: player.rs, mana_pool.rs, zones.rs, and state.rs are all implemented with 51 total passing tests in mtg-engine.

Key types now available:

ManaPool - mana pool with colored/generic spending, atomic try_pay, restrictions
Library, Hand, Graveyard, Exile, Battlefield, Stack, CommandZone - all zone containers
CardStore - central card data storage by ObjectId
Player - full player state (life, counters, zones, mana pool, land plays, hand size, game flags)
GameState - complete game state with players, zones, turn tracking, SBA checking
StateBasedActions - SBA detection (life loss, poison, lethal damage, zero toughness, indestructible)

Task #6 (turn.rs and game.rs) is now unblocked. Starting that next.
</teammate-message>

Excellent progress from the engine teammate — 5 tasks done with 51 passing tests. Task #10 (CardRegistry) is now unblocked for the cards teammate. Let me notify them.

Used SendMessage

Current status:

Teammate	Completed	Working On	Next Up
`engine`	#1, #2, #3, #4, #5	#6 (turn.rs + game.rs)	#13 (events)
`ai`	—	#7 (PlayerDecisionMaker)	#8 (random player)
`cards`	—	#10 (unblocked, starting)	#11 (FDN cards)

The engine is well ahead of schedule. Task #6 also needs #7 (PlayerDecisionMaker trait) which the AI teammate is working on — those two should converge soon.

<teammate-message teammate_id="ai" color="green" summary="Task #21 complete, all 52 mtg-ai tests pass"> Task #21 (minimax AI player) is complete. All 52 mtg-ai tests pass.

The fix for the failing minimax_ab_alpha_beta_pruning test was a bug in the terminal node check logic in minimax_ab(). The root node's initial score was set to LOSE_SCORE (as a default for maximizing nodes), and the terminal check if node.score == WIN_SCORE || node.score == LOSE_SCORE was incorrectly triggering on it before the search could explore children. The fix removes the separate terminal check and folds it into the leaf check — a node is only a leaf/terminal if depth == 0 or node.children.is_empty(). Non-leaf nodes with children always proceed to the search loop.

I also fixed a cross-crate compilation issue: tdm.rs referenced evolving_wilds from fdn.rs which was private. Made it pub and updated the reference to super::fdn::evolving_wilds.

All my assigned tasks are now complete:

#7: PlayerDecisionMaker trait
#8: RandomPlayer + evaluator
#9: Observation/action space
#20: Heuristic player
#21: Minimax player
#22: PyO3 + Gymnasium

Note: there's a pre-existing extra_turns_lifo test failure in mtg-engine that belongs to the engine teammate.

Files modified:

/mnt/dest-btrfs/home/jc/src/mage/mtg-rl/mtg-ai/src/minimax_player.rs (line 249-254: fixed leaf/terminal check)
/mnt/dest-btrfs/home/jc/src/mage/mtg-rl/mtg-cards/src/sets/fdn.rs (line 125: made evolving_wilds pub)
/mnt/dest-btrfs/home/jc/src/mage/mtg-rl/mtg-cards/src/sets/tdm.rs (line 18: use super::fdn::evolving_wilds)

</teammate-message>

The AI teammate has finished all 6 of their tasks — impressive. Let me check overall status and coordinate.

Listed

Good picture. 12 of 26 tasks completed. The engine's Phase 2 tasks (#13-17) are on the critical path now. Let me notify the engine about the test failure and redirect the AI teammate to help with the bottleneck.

Used SendMessage

Status looks good. The AI teammate finished all 6 tasks and is idle. The critical path is now the engine's Phase 2 work (#13→#14→#15/#16→#17). Engine and cards are both active. I've notified the engine about the test failure and offered the AI teammate's help. Waiting for responses before reassigning work.

<teammate-message teammate_id="ai" color="green"> {"type":"idle_notification","from":"ai","timestamp":"2026-02-13T17:46:04.868Z","idleReason":"available"} </teammate-message> <teammate-message teammate_id="ai" color="green" summary="All 6 assigned tasks already complete, available for new work"> Hi — I believe this message may be from earlier in our session. All my assigned tasks are already complete:

#7: PlayerDecisionMaker trait (completed)
#8: RandomPlayer + evaluator (completed)
#9: Observation/action space (completed)
#20: Heuristic player (completed)
#21: Minimax player (completed, just fixed the last failing test)
#22: PyO3 + Gymnasium (completed)

All 52 mtg-ai tests pass, plus 2 mtg-cards tests. The only failure in the workspace is extra_turns_lifo in mtg-engine which belongs to the engine teammate.

I'm available for any new work. The remaining tasks on the board are blocked on engine (#6 -> #13 -> #14 chain) or cards (#10 -> #11, #12). If there's anything else I can help with — like assisting with the game event system (#13) or helping unblock the engine/cards work — just let me know.
</teammate-message>

<teammate-message teammate_id="engine" color="blue" summary="Task #6 done: turn manager and game loop implemented"> Task #6 complete: turn.rs and game.rs are implemented with 64 total passing tests in mtg-engine.

Key types now available:

TurnManager - full MTG turn state machine (13 steps, phase mapping, extra turns LIFO, end-turn-early, first strike step toggling)
PriorityTracker - tracks consecutive passes for stack resolution
Game - top-level game runner with:
- new_two_player() constructor taking deck configs and decision makers
- run() method that plays a full game to completion
- Turn-based actions (untap, draw, cleanup/discard, damage removal)
- Priority loop (pass/play land/cast spell/resolve stack)
- State-based action processing (life, poison, lethal damage, 0 toughness, indestructible)
- Legal action computation (lands, sorcery/instant timing, mana payment check)
- Stack resolution (permanent spells enter battlefield, non-permanents to graveyard)

The game_runs_to_completion test verifies that two AlwaysPassPlayers play a game that ends by decking.

Task #13 (events.rs) is now unblocked. Starting that next.
</teammate-message>

<teammate-message teammate_id="ai" color="green"> {"type":"idle_notification","from":"ai","timestamp":"2026-02-13T17:46:21.087Z","idleReason":"available"} </teammate-message> <teammate-message teammate_id="ai" color="green"> {"type":"idle_notification","from":"ai","timestamp":"2026-02-13T17:46:25.601Z","idleReason":"available"} </teammate-message> <teammate-message teammate_id="ai" color="green"> {"type":"idle_notification","from":"ai","timestamp":"2026-02-13T17:46:29.634Z","idleReason":"available"} </teammate-message> <teammate-message teammate_id="ai" color="green"> {"type":"idle_notification","from":"ai","timestamp":"2026-02-13T17:46:33.081Z","idleReason":"available"} </teammate-message> <teammate-message teammate_id="ai" color="green"> {"type":"idle_notification","from":"ai","timestamp":"2026-02-13T17:46:36.877Z","idleReason":"available"} </teammate-message> <teammate-message teammate_id="ai" color="green"> {"type":"idle_notification","from":"ai","timestamp":"2026-02-13T17:46:39.807Z","idleReason":"available"} </teammate-message> <teammate-message teammate_id="ai" color="green"> {"type":"idle_notification","from":"ai","timestamp":"2026-02-13T17:46:42.820Z","idleReason":"available"} </teammate-message> <teammate-message teammate_id="ai" color="green"> {"type":"idle_notification","from":"ai","timestamp":"2026-02-13T17:46:46.393Z","idleReason":"available"} </teammate-message> <teammate-message teammate_id="ai" color="green"> {"type":"idle_notification","from":"ai","timestamp":"2026-02-13T17:46:52.662Z","idleReason":"available"} </teammate-message> <teammate-message teammate_id="ai" color="green"> {"type":"idle_notification","from":"ai","timestamp":"2026-02-13T17:46:58.242Z","idleReason":"available"} </teammate-message> <teammate-message teammate_id="engine" color="blue" summary="Task #13 done: events.rs with 100 event types implemented"> Task #13 complete: events.rs implemented with 72 total passing tests in mtg-engine.

Key types now available:

EventType enum — ~100 event types covering turn structure, zone changes, spells/abilities, damage, life, combat, permanents, counters, tokens, lands, control, targeting, and more
GameEvent struct with builder pattern: target_id, source_id, player_id, amount, flag, data, zone, prevented, applied_effects
Convenience constructors: damage_player, damage_permanent, gain_life, lose_life, draw_card, discard_card, zone_change, spell_cast, enters_battlefield, dies, destroy_permanent, add_counters, tap, declare_attacker, declare_blocker
EventLog — event accumulator for triggered ability checking

Task #14 (priority system and ability/effect framework) is now unblocked. Starting that next.
</teammate-message>

<teammate-message teammate_id="ai" color="green"> {"type":"idle_notification","from":"ai","timestamp":"2026-02-13T17:48:24.791Z","idleReason":"available"} </teammate-message>

The engine is flying — 8 tasks done, now on #14 (abilities framework). The AI teammate needs work. Let me redirect them to help with the large card implementation workload that's about to unblock.

Used TaskUpdate

Used SendMessage

Current status:

Teammate	Completed	Working On	Next Up
`engine`	#1-6, #13 (8 tasks)	#14 (priority + abilities)	#15 (combat), #16 (filters)
`ai`	#7-9, #20-22 (6 tasks)	#12 (TLA/TDM/ECL Tier 1 cards)	—
`cards`	—	#10 (CardRegistry)	#11 (FDN cards)

14 of 26 tasks complete. Critical path is #14 → #15/#16 → #17 → #23 (full game loop). The engine is moving fast through it. Redirecting the idle AI teammate to card work parallelizes the upcoming card bottleneck (#11 + #12 = ~470 cards).

<teammate-message teammate_id="engine" color="blue" summary="Task #14 done: ability/effect framework with 40+ effect types"> Task #14 complete: abilities.rs and effects.rs implemented with 86 total passing tests in mtg-engine.

Key types now available:

abilities.rs:
- Cost enum (Mana, TapSelf, PayLife, SacrificeSelf, Discard, etc.)
- Effect enum (~40 effect variants: DealDamage, GainLife, Destroy, DrawCards, AddCounters, CreateToken, BoostUntilEndOfTurn, GainKeyword, CounterSpell, etc.)
- TargetSpec enum (None, Creature, CreatureOrPlayer, Permanent, Spell, etc.)
- Ability struct with constructors: activated(), triggered(), static_ability(), mana_ability(), spell()
- StaticEffect enum (Boost, GrantKeyword, CantAttack, CostReduction, etc.)
- AbilityStore — indexed by AbilityId and source ObjectId, with triggered_by() and mana_abilities_for()
effects.rs:
- ContinuousEffect struct with 7-layer system (Layer/SubLayer), timestamps, durations
- EffectModification enum (CopyObject, ChangeControl, AddType, AddKeyword, ModifyPowerToughness, etc.)
- ContinuousEffects manager with layer-based queries and timestamp ordering
- ReplacementEffect struct (Prevent, ExileInstead, ModifyAmount, EnterTapped, etc.)
- ReplacementEffects manager

Cards teammate: you can now define card abilities using these types. Example:

rust

Tasks #15, #16, #17 are now unblocked.
</teammate-message>

Great progress — #15, #16, and partially #17 are now unblocked. Let me notify the cards teammate about the new ability API they can use.

Used SendMessage

Current status — 15 of 26 tasks complete:

Teammate	Completed	Working On	Next Up
`engine`	#1-6, #13, #14 (9 tasks)	#15 (combat) + #16 (filters)	#17 (building-block abilities)
`ai`	#7-9, #20-22 (6 tasks)	#12 (TLA/TDM/ECL Tier 1 cards)	—
`cards`	—	#10 (CardRegistry)	#11 (FDN cards)

The engine is on a tear — 9 tasks done. With #14 complete, #15 and #16 can now run in parallel. The two card teammates (#11 + #12) will have the full ability API available when they start writing cards.

<teammate-message teammate_id="engine" color="blue" summary="Task #16 complete: filters, targets, watchers"> Task #16 (filters.rs, targets.rs, watchers.rs) is complete. All 128 mtg-engine tests pass.

New modules:

filters.rs: Composable predicate-based filter system (Predicate enum with And/Or/Not combinators, Filter wrapper with matches_permanent/matches_card, pre-built filters like any_creature, creature_you_control, nonland_permanent, etc.)
targets.rs: Target definitions (TargetDefinition with zone, filter, min/max targets, is_targeted) and selected targets tracking (SelectedTargets with object/player target entries, legality marking)
watchers.rs: WatcherManager with built-in per-turn PlayerTurnStats (spells cast, cards drawn, life gained/lost, creatures died, entered/left battlefield, attackers) and GameTurnStats, plus CustomWatcher for card-specific tracking with scope filtering

Task #17 (common building-block abilities and effects) is now unblocked. Starting that next.
</teammate-message>

Engine continues to crush it — 10 tasks done, 128 tests passing. Task #17 (building-block abilities) is the last piece before the full game loop (#23) can be assembled. Once that's done along with #15 (combat), we hit the major integration milestone.

16 of 26 tasks complete.

Teammate	Completed	Working On
`engine`	#1-6, #13, #14, #16 (10)	#15 (combat) + #17 (building-block abilities)
`ai`	#7-9, #20-22 (6)	#12 (TLA/TDM/ECL Tier 1 cards)
`cards`	—	#10 (CardRegistry)

<teammate-message teammate_id="engine" color="blue" summary="Task #17 complete: building-block abilities/effects"> Task #17 (common building-block abilities and effects) is complete. All 141 mtg-engine tests pass.

Added to abilities.rs:

Triggered ability builders: enters_battlefield_triggered, dies_triggered, attacks_triggered, combat_damage_to_player_triggered, beginning_of_upkeep_triggered, beginning_of_end_step_triggered, spell_cast_triggered, other_creature_etb_triggered, any_creature_dies_triggered
Effect builders: deal_damage, draw_cards, gain_life, lose_life, boost_until_eot, create_token, counter_spell, scry, mill, discard_cards, bounce, reanimate, add_p1p1_counters, tap_target, untap_target, destroy_all, damage_opponents, search_library, gain_control, gain_protection, indestructible, hexproof, etc.
Static effect builders: boost_controlled, grant_keyword_controlled, cant_block, cant_attack, cost_reduction
Cost builders: pay_mana, tap_self, sacrifice_self, sacrifice_other, pay_life, discard, exile_from_hand, exile_from_graveyard, remove_counters

Tasks #18, #19, and #23 are now unblocked. Starting task #23 (complete game loop) next.
</teammate-message>

Massive milestone — all Phase 2 engine infrastructure is done. Let me check the full status and notify the card teammates.

Listed

20 of 26 tasks complete. Engine has #15 done too (combat). All core infrastructure is built. Let me assign the AI teammate to the newly unblocked tasks and notify both card teammates.

Used TaskUpdate

Used SendMessage

20 of 26 tasks complete. We're entering Phase 3 — integration and complex cards.

Teammate	Completed	Working On	Next Up
`engine`	#1-6, #13-17 (12)	#23 (full game loop integration)	#25 (tests), #26 (perf)
`ai`	#7-9, #12, #20-22 (7)	#18 (set-specific keywords)	help with #19 or #25
`cards`	#10 (1)	#11 (FDN cards)	#19 (Tier 2 cards)

The critical path is now #23 (full game loop) — once that's done, testing (#25) and perf (#26) can start. All three teammates have active work.

<teammate-message teammate_id="cards" color="yellow" summary="Completed FDN 154 cards, all tests pass"> Completed tasks #11 and #12:

Task #11 — FDN curated subset (~150 cards): Done. FDN now has 154 cards total (149 unique + 5 basic lands). Added 79 Tier 2 cards including:

14 vanilla/keyword creatures (Savannah Lions, Gigantosaurus, Shivan Dragon, Juggernaut, etc.)
32 creatures with abilities (Guttersnipe, Reclamation Sage, Inspiring Overseer, Brineborn Cutthroat, etc.)
23 instants (Giant Growth, Unsummon, Cancel, Negate, Opt, Snakeskin Veil, etc.)
9 sorceries (Day of Judgment, Duress, Dragon Fodder, Chart a Course, etc.)
1 enchantment (Pacifism)

Task #12 — Tier 1 TLA/TDM/ECL: Already completed last session. All Tier 1 cards from tier files implemented.

All 5 cargo tests pass. Current set card counts:

FDN: 154 cards
TLA: 52 cards (someone added 32 more since last session)
TDM: 65 cards
ECL: 40 cards

Updated test assertions to use >= thresholds so they stay robust as teammates add cards.

Ready for next task — I can work on Task #18 (set-specific keywords) or #19 (Tier 2 for TLA/TDM/ECL) if their blockers (#17) are resolved.
</teammate-message>

Cards teammate delivering nicely — 154 FDN cards done. Task #19 (Tier 2 cards) is unblocked and already assigned to you. Let me confirm.

Used TaskUpdate

Used SendMessage

21 of 26 tasks complete.

Teammate	Completed	Working On	Next Up
`engine`	12 tasks	#23 (full game loop)	#25 (tests), #26 (perf)
`ai`	7 tasks	#18 (set-specific keywords)	help with #19 or #24
`cards`	2 tasks (#10, #11)	#19 (Tier 2 cards)	#24 (Tier 3+4)

All three teammates are active on Phase 3 work. The engine is integrating the full game loop (#23) — that's the last major gating task before testing and polish.

<teammate-message teammate_id="engine" color="blue"> {"type":"idle_notification","from":"engine","timestamp":"2026-02-13T18:31:09.681Z","idleReason":"interrupted"} </teammate-message>

The engine teammate was interrupted while working on task #23 (full game loop). Let me check on them.

Used SendMessage

Waiting for the engine teammate's response. Task #23 is on the critical path — #24 (complex cards), #25 (tests), and #26 (performance) are all blocked on it.

200 of 601

Plan: Port XMage to Rust for RL AI Training

Context

Project Structure

Team Structure (3 teammates)

Teammate 1: engine — Core Game Engine

Teammate 2: ai — AI Players + PyO3/Gymnasium

Teammate 3: cards — Card Implementations for FDN, TLA, TDM, ECL

Phase 1: Foundation (all teams start in parallel)

Engine teammate

AI teammate

Cards teammate

Phase 2: Core Systems

Engine teammate

AI teammate

Cards teammate

Phase 3: Integration & Complex Cards

Engine teammate

AI teammate

Cards teammate

Phase 4: Testing & Polish

Test strategy: Port core + cherry-pick + gap-fill

Key Design Decisions

Critical Source Files (Java → Rust reference)

Plan: Port XMage to Rust for RL AI Training

Context

Project Structure

Team Structure (3 teammates)

Teammate 1: engine — Core Game Engine

Teammate 2: ai — AI Players + PyO3/Gymnasium

Teammate 3: cards — Card Implementations for FDN, TLA, TDM, ECL

Phase 1: Foundation (all teams start in parallel)

Engine teammate

AI teammate

Cards teammate

Phase 2: Core Systems

Engine teammate

AI teammate

Cards teammate

Phase 3: Integration & Complex Cards

Engine teammate

AI teammate

Cards teammate

Phase 4: Testing & Polish

Test strategy: Port core + cherry-pick + gap-fill

Key Design Decisions

Critical Source Files (Java → Rust reference)

Teammate 1: `engine` — Core Game Engine

Teammate 2: `ai` — AI Players + PyO3/Gymnasium

Teammate 3: `cards` — Card Implementations for FDN, TLA, TDM, ECL

Teammate 1: `engine` — Core Game Engine

Teammate 2: `ai` — AI Players + PyO3/Gymnasium

Teammate 3: `cards` — Card Implementations for FDN, TLA, TDM, ECL