Here is a list of all EventHandler events that the controller uses, along with a brief description of what each event is used for and its parameters, if it has any:

Event NameParametersDescription
OnAbilityMessageCanStartAbility ability, bool canStartThe ability can start or no longer stop.
OnAbilityUnequipItemCompleteItem item, int slotIDThe item has been unequipped from the slot slotID.
OnAbilityWillEquipItemItem item, int slotIDThe item will be equipped in the slot slotID.
OnAddCrosshairsSpreadbool start, bool fromRecoilThe crosshair spread should be started/stopped, either from recoil or set to max spread.
OnAddSecondaryCameraForceVector3 positionalForce, Vector3 rotationalForce, float restAccumulationAdds a secondary positional and rotational force to the ViewTypes.
OnAddSecondaryForceint slotID, Vector3 positionalForce, Vector3 rotationalForce, bool globalForceAdds a positional and rotational force to the IK target.
OnAimAbilityAimbool aimThe aim ability is/is not aiming.
OnAimAbilityStartbool aim, bool inputStartThe aim ability was started/stopped. inputStart describes whether it was started/stopped from user input.
OnAnimatorSnappedThe animator has been snapped.
OnAnimatorWillSnapThe animator will snap.
OnAnchorOffsetUpdatedThe camera’s anchor offset value has been changed.
OnAttributeModifierAutoUpdateEnabledAttributeModifier attributeModifier, bool enableThe attributeModifier‘s auto-update has been enabled/disabled.
OnAttributeReachedDestinationValueAn attribute has reached its destination value.
OnAttributeUpdateValueAttribute attributeThe attribute‘s value has been changed.
OnCameraAttachCharacterGameObject characterThe character has been attached to the camera.
OnCameraChangePerspectivesbool firstPersonPerspectiveThe camera has swithced between first and third person perspectives.
OnCameraChangeViewTypesViewType viewType, bool activateThe viewType was activated/deactivated.
OnCameraRotationalForceVector3 forceAdd the rotational force to the camera.
OnCameraWillChangePerspectivesbool firstPersonPerspectiveThe camera will switch between first and third person perspectives.
OnCameraZoombool zoomThe camera has zoomed in/out.
OnCharacterAbilityActiveAbility ability, bool activeThe ability has been activated/deactivated.
OnCharacterActivatebool activeThe character itself has been activated/deactivated.
OnCharacterAttachCameraCameraController cameraControllerThe cameraController has been attached to the character.
OnCharacterAttachLookSourceILookSource lookSourceThe ILookSource has been attached to the character.
OnCharacterChangeMovementTypeMovementType movementTypeThe character’s movement type will be changed to movementType.
OnCharacterChangeMovingPlatformsTransform platformThe character has been attached to the moving platform.
OnCharacterChangePerspectivesbool firstPersonPerspectiveThe camera will switch between first and third person perspectives.
OnCharacterChangeTimeScalebool valueThe character’s time scale will be changed to value.
OnCharacterChangeUpdateLocationUpdateLocation updateLocationThe character’s update location will be changed to the specified updateLocation.
OnCharacterDestroyedThe Ultimate Character Locomotion component has been destroyed.
OnCharacterEnterUIZonebool inUIZoneThe character has entered/exited a zone which should show the UI and cursor.
OnCharacterForceIndependentLookbool independentLookIndependent look will be enabled/disabled on the character to allow the ability to have control over rotation.
OnCharacterGroundedbool groundedThe character’s grounded state has changed to grounded.
OnCharacterImmediateTransformChangebool snapAnimatorThe character’s transform position/rotation has been immediately changed.
OnCharacterIndependentFadebool enable, bool revertFadeAnother object has started or stopped taking control of the character fade.
OnCharacterItemAbilityActiveItemAbility itemAbility, bool activeThe itemAbility has been activated/deactivated.
OnCharacterLandfloat heightThe character has landed from height.
OnCharacterLeanfloat distance, float tilt, float itemTiltMultiplierThe character is leaning the specified distance and tilt amount.
OnCharacterMovingbool movingThe character has either started or stopped moving.
OnCharacterSnapAnimatorThe character’s animator should be snapped to match its current state.
OnDeathVector3 position, Vector3 force, GameObject attackerAn object with the Health component has died. See OnHealthDamage.
OnEnableGameplayInputbool enableGameplay input should be enabled/disabled.
OnEquipUnequipItemSetIndexChangeint itemSetIndexThe active ItemSet index has changed to itemSetIndex.
OnEquipUnequipVerifyUnequipItemint itemSetCategoryIndex, int slotIDVerify that the unequipping item specified by the itemSetCategoryIndex in the slot slotID still needs to be unequipped.
OnFirstPersonPerspectiveActivateFirstPersonPerspectiveItem perspectiveItem, bool activeThe first person perspective item has been activated/deactivated.
OnHealthDamagefloat amount, Vector3 position, Vector3 force, GameObject attacker, Collider hitColliderDamage has been applied to the Health component.
OnHealthHealfloat amountThe Health component has been healed by amount.
OnHeightChangeAdjustHeightfloat heightAdjustmentThe character’s height has been adjusted by the specified amount.
OnInputControllerConnectedbool controllerConnectedA controller has been connected/disconnected.
OnInventoryAddItemItem itemThe item has been added to the inventory.
OnInventoryAdjustItemIdentifierAmountIItemIdentifier itemIdentifier, int remainingThe amount of the item itemIdentifier has been adjusted, leaving remaining of that item left.
OnInventoryEquipItemItem item, int slotIDThe item in slot slotID has been equipped.
OnInventoryPickupItemItem item, int amount, bool immediatePickup, bool forceEquipThe amount of item has been picked up and will/will not be picked up immediately and forcefully equipped.
OnInventoryPickupItemIdentifierIItemIdentifier itemIdentifier, int amount, bool immediatePickup, bool forceEquipThe amount of item itemIdentifier has been picked up and will/will not be picked up immediately and forcefully equipped.
OnInventoryRemoveItem
OnInventoryRespawnedThe inventory has respawned.
OnInventoryUnequipItemItem item, int slotIDThe item in slot slotID has been unequipped.
OnItemPickupStartPickupAn ItemPickup has been started to be picked up.
OnItemPickupStopPickupAn ItemPickup has been stopped to be picked up.
OnItemSetIndexChangeint categoryIndex, int itemSetIndexThe ItemSetManager has changed the category categoryIndex‘s active ItemSet index to itemSetIndex.
OnItemSetManagerUpdateItemSetint categoryIndex, int itemSetIndexUpdates the currently active item set in the category categoryIndex to itemSetIndex.
OnItemSetManagerUpdateNextItemSetint categoryIndex, int prevItemSetIndex, int itemSetIndexUpdates the next item set in category categoryIndex, including the previous and next item set indices.
OnItemShowFullScreenUIint fullScreenUIID, bool showFullScreenUIShows/hides the full screen UI object based on its UI ID.
OnItemStartUseIUsableItem item, bool useThe item is starting/stopping use.
OnItemTryReloadint slotID, IItemIdentifier consumableItemIdentifier, bool immediateReload, bool equipCheckThe item at slot slotID is trying to reload using consumableItemIdentifier.
OnItemUpdateDominantItemItem item, bool dominantItemSets the item as the dominant/not dominant item.
OnItemUseConsumableItemIdentifierItem item, IItemIdentifier consumableItemIdentifier, int remainingThe item has consumed some amount of consumableItemIdentifier, leaving remaining of those left.
OnMagicItemCastItem itemThe magic item has cast an action.
OnMagicItemImpactItem item, SurfaceImpact surfaceImpactThe magic item has collided with a surface.
OnMagicItemStartStopBeginEndActionsItem item, bool beginActions, bool startA magic item‘s begin/end actions have been started/stopped.
OnNextItemSetItem item, bool unequipOnFailureThe item wants to change to equip the next item from the item set.
OnObjectImpactfloat amount, Vector3 position, Vector3 forceDirection, GameObject attacker, object attackerObject, Collider hitColliderAn object has been impacted by another object. Used by Projectile, ShootableWeapon and MeleeWeapon.
OnObjectPickedUpObjectPickup objectPickupThe objectPickup has been picked up.
OnRespawnThe object has respawned.
OnShieldImpactShield shield, object sourceThe shield has been impacted by object.
OnShootableWeaponShowProjectileGameObject projectile, bool showThe ShootableWeapon ItemAction has shown or hidden a projectile.
OnShowUIbool showThe UI should be shown/hidden.
OnStateChangeGameObject gameObject, string stateName, bool activeThe gameObject has activated/deactivated the stateName state.
OnStoredInputAbilityResetStoredInputsResets the ability’s stored user inputs.
OnTryRecenterTrackingVR only – The camera’s rotation has changed, so tracking recentering should occur.
OnUseAbilityStartbool start, Use useAbilityThe specified useAbility has been started/stopped.
OnUseAbilityUsedItemIUsableItem itemThe Use ability has used item.
OnWillRespawnThe object will respawn.