STATE_ROLLBACK — SolumWorld / Zipvilization
Purpose
Define how SolumWorld handles invalid states without breaking immutability.
Rollback is not time travel. Rollback is state selection.
Core Rule
Past states are never modified. Rollback selects a previous valid state as the new head.
When Rollback Is Allowed
Rollback can occur only if:
- A state fails invariant validation
- A transition cannot be deterministically replayed
- Corruption or inconsistency is detected
Rollback Mechanism
- Detect invalid state
- Identify last valid state
- Set last valid state as active head
- Discard invalid forward states from canonical view
Important:
- Discarded states remain archived
- They are excluded from canonical history
Rollback Scope
- Rollback always applies to the entire world state
- Partial rollback is forbidden
Rollback vs Evolution
- Evolution is forward-only
- Rollback does not reverse evolution; it rejects invalid futures
Safety Guarantees
- No invariant-breaking state can persist
- Canonical history remains linear
- Determinism is preserved
Canonical Status
Rollback protects SolumWorld integrity. It is a safeguard, not a gameplay mechanic.