Save System - Dual Files, Codec and World State

Dual-file architecture

The save layer splits into two distinct files:

File	Holds
PlayerSaveFile	Character build, inventory, equipment, spell upgrades, skill tree, Pet Pen contents (PetPenSaveData)
WorldSaveFile	Scene/object state — opened chests, harvested nodes, world events, build placement (BuildItemSaveData)

Splitting character from world is what makes co-op drop-in viable: your character travels into another player’s world file.

Encoding layer

SaveCodec sits between the object graph and disk — saves are encoded, not plain JSON. SaveFiles, SaveNameKind, SaveNameVerdict and SaveNameRules implement slot naming and validation (reserved/invalid name handling). SaveOnQuit writes on exit; corruption recovery specifics aren’t visible in code.

What this means in practice

• Your character is portable across worlds (consistent with the Relay co-op model)
• World state (which of the 1,784 POIs you’ve cleared) persists per world
• Pet Pen data rides with the player file — your pets follow you into a friend’s world
• Editing saves externally requires reversing SaveCodec, which is non-trivial by design