Save/Load Service: Blueprint architecture

What/Why: Reliable saves without tangling logic; centralize in a GameInstanceSubsystem with async throttling.

Prereqs

• Project Settings → enable SaveGame usage

Steps

1. Create BP_SaveService (GameInstanceSubsystem)

• Events: RequestSave(ProfileId), RequestLoad(ProfileId), OnSaved, OnLoaded
• Internals: queue requests; Timer to process one at a time (avoid spikes)

2. Define SaveGame classes (BP)

• SG_PlayerProfile: progression, options
• SG_WorldState: level streaming state, global flags

3. Callers

• On level transition or checkpoint, call RequestSave
• On startup, call RequestLoad → broadcast loaded data

4. Versioning

• Use a SaveVersion int; if mismatch, run migration or defaults

Data

• Keep references as IDs; resolve to data assets at runtime

Networking

• Server-authoritative saves; clients request via RPC if needed

Performance

• Compress large blobs only off the game thread (async blueprint nodes)

Testing

• “Dirty flag” changes trigger a queued save
• Quit/restart → state restored properly

Suggested prompts

• “UE 5.6 Blueprints only. Create BP_SaveService (GameInstanceSubsystem) with queued RequestSave/RequestLoad. Show events and timers to throttle saves.”
• “How do I version SaveGame data with a SaveVersion int and migrate safely?”
• “Outline a test plan to validate save requests, throttle behavior, and load-on-startup.”
• “List pitfalls for save spikes and how to avoid blocking the game thread.”

Prompts for this example

• “Provide Blueprint nodes to enqueue a save on checkpoint and emit OnSaved when complete.”
• “Show how to load SG_PlayerProfile on startup and broadcast the data to interested systems.”