Instance vs World: Boundary Conditions in Persistent Simulations
When a system is described as a persistent world, a peculiar cognitive instability immediately appears.
The world is perceived as continuous. Interaction is perceived as discrete.
This tension is not a flaw of interface design. It is a structural consequence of a missing conceptual layer:
Instance
Without distinguishing instance from world, persistence becomes logically incoherent.
World Is Not a Runtime Container
In simulation theory, a world is not a scene, environment, or narrative setting.
A world is a state space.
A state space defines:
- The set of all possible system states
- The transition rules governing state evolution
Crucially:
A world does not start. A world does not stop.
It evolves.
Interpreting a world as a running program imports software intuitions that do not apply to dynamical systems.
Instance Is Not a Copy of the World
Instance is frequently misinterpreted as:
A duplicated world — or an isolated version of reality.
Both interpretations are incorrect.
An instance is not a replicated state space.
An instance is an access boundary.
More precisely:
Instance defines the interaction window through which an observer couples into an evolving system.
The world persists. The instance permits interaction.
Boundary Conditions and Observer Coupling
In physical simulation models, boundary conditions govern how a system interacts with external agents.
World → Internal evolution Instance → External coupling interface
This interface performs three structural functions.
Temporal Cross-Section
World evolution is continuous.
Instance provides access to a temporal slice of that evolution.
Resetting an instance does not reset the world because:
Instances do not possess temporal continuity. Worlds do.
Causal Injection Point
State-dynamic systems evolve through perturbations:
Action → State perturbation → Propagation → EmergenceInstance defines where perturbations may legally enter the system.
The world does not respond to the observer.
The world responds to state changes.
Observational Constraint
Observation is itself a system interaction.
Instance constrains:
- What state variables are visible
- What perturbations are permitted
- What history is accumulated
It is not a container of reality.
It is a filter of interaction.
Resolving the Persistence Paradox
Persistent worlds often trigger a familiar objection:
If the world persists, why can interaction restart?
The paradox dissolves once layers are separated.
Persistence belongs to the world. Restart belongs to the instance.
No contradiction exists.
Reset as Boundary Reinitialization
Resetting an instance is not erasure.
It is boundary reinitialization.
The world state remains intact.
Only the observer coupling is reconstructed.
Instance as Ontological Stabilizer
Direct exposure of the world to the observer collapses simulations into:
Conversation systems — or game loops.
Instance prevents this collapse.
It maintains the structural asymmetry:
World as subject Observer as perturbation source
The structural conditions under which game loops emerge from persistent worlds illustrate precisely why this asymmetry cannot be maintained without the Instance layer. Without it, the observer becomes the organizing principle — and world-centered causality dissolves. The mechanics vs dynamics distinction follows the same boundary: mechanics organize systems around the observer's interaction loop; dynamics organize systems around the world's evolving state.
Structural Conclusion
World defines the evolving state space.
Instance defines the interaction boundary.
World governs how systems evolve.
Instance governs how observers participate in evolution.
Persistence is a world property. Interaction is an instance behavior.
Only when these layers are separated does the simulation achieve ontological stability.
