BPC_KeyItemSystem — Key Item System
Parent Class: ActorComponent
Category: Inventory
Target UE Version: 5.5–5.7
Build Phase: 3 — Inventory
1. Overview
BPC_KeyItemSystem manages key items — story-critical objects that unlock doors, trigger narrative events, or are required for puzzle completion. Tracks acquired keys, provides query for door/puzzle unlock checks, and supports key usage notifications.
2. Variables
| Variable |
Type |
Description |
AcquiredKeys |
TArray<FGameplayTag> |
Tags of all acquired key items |
bShowKeyNotifications |
bool |
Toast on key pickup |
KeyItemCategory |
E_ItemCategory |
KeyItem category filter |
3. Functions
| Function |
Description |
HasKey |
Checks if player has a specific key by tag |
AddKey |
Registers a key item acquisition |
RemoveKey |
Removes a key (if consumed) |
GetAllKeys |
Returns all acquired key tags |
CanUnlock |
Checks if player meets unlock requirements for a target |
4. Event Dispatchers
| Dispatcher |
Payload |
Description |
OnKeyAcquired |
FGameplayTag KeyTag |
New key picked up |
OnKeyUsed |
FGameplayTag KeyTag, AActor* Target |
Key used on target |
OnKeyRemoved |
FGameplayTag KeyTag |
Key consumed/removed |
5. Dependencies
| System |
Relationship |
BPC_InventorySystem |
Keys as inventory items |
BP_DoorActor |
Door unlock queries |
BP_PuzzleDeviceActor |
Puzzle unlock gates |
BPC_NarrativeStateSystem |
Key-based narrative flags |
6. Reuse Notes
- Keys use gameplay tags for generic matching (any key with same tag works)
- Supports consumable keys (removed after single use) and persistent keys
