Event Reference

📡

GCS · Events

All 43 built-in events: constant, string value, payload type, every payload field, and what usually subscribes to each.

Keep this open while wiring listeners. Every row matches the shipped GCSEventNames and GCSEventArgs source.

This page tabulates every constant in GCSEventNames and every payload class in GCSEventArgs.cs: 43 events across six groups. String values follow one rule, the constant's name prefixed with GCS_, so OnCardPlayed broadcasts as GCS_OnCardPlayed.

These are the same names the Game Card Monitor prints on its Event tab. The fastest way to learn which events a card actually raises is to play it once in Play Mode with the Monitor open:

Battle and turn events

Constant	String value	Payload	Fields	Typical use
OnBattleStarted	GCS_OnBattleStarted	None	None	Initial HUD refresh, battle start animation.
OnTurnStarted	GCS_OnTurnStarted	TurnEventArgs	TurnNumber	Start-turn UI refresh.
OnEnemyTurnStarted	GCS_OnEnemyTurnStarted	TurnEventArgs	TurnNumber	Enemy phase banner or input lock.
OnTurnEnded	GCS_OnTurnEnded	TurnEventArgs	TurnNumber	End-turn cleanup and logs.
OnDrawPhase	GCS_OnDrawPhase	TurnEventArgs	TurnNumber	Draw-phase UI and draw count effects.
OnDiscardPhase	GCS_OnDiscardPhase	TurnEventArgs	TurnNumber	Discard-phase UI and cleanup.
OnBattleEnded	GCS_OnBattleEnded	BattleEndedEventArgs	Won	Victory or defeat overlay.

---

Card events

Constant	String value	Payload	Fields	Typical use
OnCardPlayed	GCS_OnCardPlayed	CardPlayedEventArgs	Card, InstanceId, TargetUnitId	Combat log, play animation, combo counters.
OnCardModified	GCS_OnCardModified	CardModifiedEventArgs	InstanceId	Refresh cost, upgrade, or transformed card UI.
OnCardDrawn	GCS_OnCardDrawn	CardLifecycleEventArgs	InstanceId, Card	Draw animation and hand refresh.
OnCardDiscarded	GCS_OnCardDiscarded	CardLifecycleEventArgs	InstanceId, Card	Discard animation and pile refresh.
OnCardExhausted	GCS_OnCardExhausted	CardLifecycleEventArgs	InstanceId, Card	Exhaust animation and pile refresh.
OnCardRetained	GCS_OnCardRetained	CardLifecycleEventArgs	InstanceId, Card	Retain feedback.
OnCardAddedToHand	GCS_OnCardAddedToHand	CardLifecycleEventArgs	InstanceId, Card	Generated-card UI.
OnCardAddedToDeck	GCS_OnCardAddedToDeck	CardLifecycleEventArgs	InstanceId, Card	Run deck or deck-add feedback.
OnDrawPileShuffled	GCS_OnDrawPileShuffled	None	None	Shuffle animation or pile counter refresh.

---

Unit, HP, armor, damage, and energy events

Constant	String value	Payload	Fields	Typical use
OnUnitHpChanged	GCS_OnUnitHpChanged	UnitHpChangedEventArgs	UnitId, CurrentHp, MaxHp, CurrentArmor, PreviousHp, PreviousArmor	HP and armor bars.
OnUnitDied	GCS_OnUnitDied	UnitDiedEventArgs	UnitId, Tier	Death animation, rewards, target cleanup.
OnDamageDealt	GCS_OnDamageDealt	DamageEventArgs	SourceUnitId, TargetUnitId, Amount, Lethal	Outgoing damage log and hit feedback.
OnDamageTaken	GCS_OnDamageTaken	DamageEventArgs	SourceUnitId, TargetUnitId, Amount, Lethal	Incoming hit reactions.
OnArmorGained	GCS_OnArmorGained	ArmorChangedEventArgs	UnitId, Amount, CurrentArmor	Armor floating text and armor bar refresh.
OnArmorLost	GCS_OnArmorLost	ArmorChangedEventArgs	UnitId, Amount, CurrentArmor	Armor break feedback.
OnEnergyChanged	GCS_OnEnergyChanged	EnergyChangedEventArgs	CurrentEnergy, MaxEnergy	Energy UI refresh.
OnEnergyGained	GCS_OnEnergyGained	EnergyDeltaEventArgs	Amount, CurrentEnergy	Energy gain feedback.
OnEnergySpent	GCS_OnEnergySpent	EnergyDeltaEventArgs	Amount, CurrentEnergy	Card spend feedback.

---

Status events

Constant	String value	Payload	Fields	Typical use
OnStatusChanged	GCS_OnStatusChanged	StatusChangedEventArgs	UnitId, Status, Stacks	Refresh status widget.
OnStatusTicked	GCS_OnStatusTicked	StatusTickedEventArgs	UnitId, Status, Timing, StacksBefore, StacksAfter, HpBefore, HpAfter	Tick animation and combat log.
OnStatusInflicted	GCS_OnStatusInflicted	StatusTransitionEventArgs	UnitId, Status, Stacks, SourceUnitId	Status apply animation.
OnStatusExpired	GCS_OnStatusExpired	StatusTransitionEventArgs	UnitId, Status, Stacks, SourceUnitId	Natural expiration animation.
OnStatusRemoved	GCS_OnStatusRemoved	StatusTransitionEventArgs	UnitId, Status, Stacks, SourceUnitId	Cleanse or removal animation.

---

Enemy and delayed trigger events

Constant	String value	Payload	Fields	Typical use
OnEnemyUnitIntentChanged	GCS_OnEnemyUnitIntentChanged	EnemyUnitIntentChangedEventArgs	UnitId, Intents	Intent widget refresh.
OnEnemyUnitActing	GCS_OnEnemyUnitActing	EnemyUnitActingEventArgs	UnitId, Intent	Attack telegraphs such as the demo's lunge animation.
OnEnemyUnitSummoned	GCS_OnEnemyUnitSummoned	EnemyUnitSummonedEventArgs	SummonerId, SummonedUnitId, Tier	Summon animation and layout refresh.
OnEnemyPhaseChanged	GCS_OnEnemyPhaseChanged	EnemyPhaseChangedEventArgs	UnitId, OldIndex, NewIndex	Enemy behavior phase UI.
OnDelayedTriggerScheduled	GCS_OnDelayedTriggerScheduled	DelayedTriggerScheduledEventArgs	SourceUnitId, RemainingTurns, ActionTypeName	Countdown indicator.
OnDelayedTriggerFired	GCS_OnDelayedTriggerFired	DelayedTriggerFiredEventArgs	SourceUnitId, ActionTypeName	Delayed effect activation feedback.
OnDelayedTriggerCancelled	GCS_OnDelayedTriggerCancelled	DelayedTriggerCancelledEventArgs	SourceUnitId	Remove countdown UI.

---

Reward and choice events

Constant	String value	Payload	Fields	Typical use
OnBattleRewardOffered	GCS_OnBattleRewardOffered	BattleRewardOfferedEventArgs	CardCandidates	Show the reward picker.
OnBattleRewardSelected	GCS_OnBattleRewardSelected	BattleRewardSelectedEventArgs	Choice, SelectedCard	Close the reward picker and update the run deck.
OnBattleRewardSkipped	GCS_OnBattleRewardSkipped	None	None	Close the reward picker.
OnEffectChoiceOffered	GCS_OnEffectChoiceOffered	EffectChoiceOfferedEventArgs	PromptText, Candidates, AllowSkip	Show the FlowGraph choice picker.
OnEffectChoiceSelected	GCS_OnEffectChoiceSelected	EffectChoiceSelectedEventArgs	SelectedIndex	Close the choice picker and log the selection.
OnEffectChoiceSkipped	GCS_OnEffectChoiceSkipped	None	None	Close the choice picker.

---

Payload types

Payload type	Fields
TurnEventArgs	int TurnNumber
CardPlayedEventArgs	GameCard Card, int InstanceId, int? TargetUnitId
CardModifiedEventArgs	int InstanceId
UnitHpChangedEventArgs	int UnitId, int CurrentHp, int MaxHp, int CurrentArmor, int PreviousHp, int PreviousArmor
UnitDiedEventArgs	int UnitId, string Tier
StatusChangedEventArgs	int UnitId, GameStatus Status, int Stacks
StatusTickedEventArgs	int UnitId, GameStatus Status, string Timing, int StacksBefore, int StacksAfter, int HpBefore, int HpAfter
EnemyUnitIntentChangedEventArgs	int UnitId, IReadOnlyList<IntentEntry> Intents
EnemyUnitActingEventArgs	int UnitId, IntentTag Intent
EnemyPhaseChangedEventArgs	int UnitId, int OldIndex, int NewIndex
EnergyChangedEventArgs	int CurrentEnergy, int MaxEnergy
DelayedTriggerScheduledEventArgs	int SourceUnitId, int RemainingTurns, string ActionTypeName
DelayedTriggerFiredEventArgs	int SourceUnitId, string ActionTypeName
DelayedTriggerCancelledEventArgs	int SourceUnitId
BattleRewardOfferedEventArgs	IReadOnlyList<GameCard> CardCandidates
BattleRewardSelectedEventArgs	RewardChoice Choice, GameCard SelectedCard
EffectChoiceOfferedEventArgs	string PromptText, IReadOnlyList<ChoiceCandidate> Candidates, bool AllowSkip
EffectChoiceSelectedEventArgs	int SelectedIndex
BattleEndedEventArgs	bool Won
EnemyUnitSummonedEventArgs	int SummonerId, int SummonedUnitId, string Tier
CardLifecycleEventArgs	int InstanceId, GameCard Card
DamageEventArgs	int SourceUnitId, int TargetUnitId, int Amount, bool Lethal
ArmorChangedEventArgs	int UnitId, int Amount, int CurrentArmor
EnergyDeltaEventArgs	int Amount, int CurrentEnergy
StatusTransitionEventArgs	int UnitId, GameStatus Status, int Stacks, int SourceUnitId

---

Shortcut coverage

Every event in the tables above except one has a GCSApi shortcut with the same name, so GCSEventNames.OnUnitHpChanged pairs with GCSApi.OnUnitHpChanged(...). Four subscription forms cover everything:

• GCSApi.OnBattleStarted(handler) and the other payload-free shortcuts take an Action.
• GCSApi.OnUnitHpChanged(args => ...) and the other typed shortcuts take an Action<TArgs>.
• GCSApi.Subscribe<TArgs>(GCSEventNames.SomeEvent, handler) subscribes by name with a typed handler.
• GCSApi.Subscribe(GCSEventNames.SomeEvent, handler) subscribes by name without a payload.

The exception is OnEnemyUnitActing, which has no shortcut. Subscribe to it by name with its payload type:

var sub = GCSApi.Subscribe<EnemyUnitActingEventArgs>(
    GCSEventNames.OnEnemyUnitActing,
    args => PlayAttackWindup(args.UnitId, args.Intent));

Custom events raised through GCSApi.RaiseGameEvent have no shortcuts either; subscribe to them by name.

---

Nullability notes

Field	Can be null	Why
CardPlayedEventArgs.TargetUnitId	Yes	Some cards play without a target; the field is int?.
GameCard fields in payloads	Rarely, but guard UI code anyway	The runtime skips null cards where it can; defensive UI costs nothing.
GameStatus fields in payloads	Rarely, but guard UI code anyway	Status databases can change while content is being authored.
IReadOnlyList payloads	Treat as non-null	The runtime supplies lists for every built-in event.

---

Event names versus FlowGraph entries

Graph entries and hooks (the On Card Played entry, the damage hooks, and the rest) are authoring-level timing points inside a graph, not channel broadcasts, so they have no GCSEventNames constant. This reference covers the runtime event channel only. For graph-side timing, see Entries and Hooks.