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PCAM-24: A Phase-Centric Action Model v2.0

For Deterministic Semantic Simulation

Abstract

This paper introduces PCAM-24 v2.0, a simulation model in which discrete phase—rather than continuous time—is the authoritative coordinate for action progression. V2.0 introduces Semantic Overlays and Phase Elasticity, allowing for overlapping gameplay properties and deterministic non-linear flow without reintroducing timing drift.

📄 YAML Data Standard v2.0 Available

Ready to implement PCAM-24? See the YAML Data Standard for the engine-agnostic schema that defines actions, semantic overlays, and elasticity rules.

1. Introduction

Modern interactive simulations—especially games—coordinate multiple subsystems that each operate on their own notion of time. Animation advances clip time, combat evaluates frame-based windows, and networking reconciles wall-clock deltas. This fragmentation produces: * Desynchronization between animation and gameplay * Brittle timing logic (floats/frames) * Ambiguous interaction adjudication

PCAM-24 proposes a different foundation: replace time as the primary semantic coordinate with discrete phase. Rather than asking "when did something happen?", PCAM-24 asks "what stage of the action is occurring?"

2. Core Concept: Phase Authority

2.1 Phase Space

PCAM-24 defines a fixed, cyclic phase space: $\(Phase \in \mathbb{Z}_{24} = \{0,1,\dots,23\}\)$ Phase advances discretely and wraps modulo 24. It is the sole authoritative coordinate for all gameplay logic.

2.2 Semantic Overlays (v2.0)

Action properties are expressed as Overlays. Multiple overlays (e.g., ACTIVE and INVULNERABLE) can coexist at the same phase, resolved by a deterministic Precedence Matrix.

2.3 Phase Elasticity (v2.0)

The phase cycle can "bend" while remaining discrete: - STALL: Hold a phase for multiple simulation ticks (e.g., hit-stop). - SKIP: Jump forward in the cycle (e.g., cancel-flow).

3. The Axioms

PCAM-24 enforces several non-negotiable axioms:

  1. Phase is Authoritative: It is the sole coordinate for ordering and adjudication.
  2. Semantic Overlays: All properties must be expressible as phase overlays.
  3. Monotonic Progression: No rewinds. Elasticity (stalls/skips) must be deterministic.
  4. Subsystem Subscription: Animation/Audio observe phase but do not drive it.
  5. Interaction by Precedence: Overlapping overlays resolve by a fixed matrix.

4. Interaction Adjudication

PCAM-24 resolves contested interactions using a precedence matrix: 1. VOID (Invulnerability) 2. COUNTER (Parry) 3. MITIGATE (Block/Armor) 4. IMPACT (Active Hit)

5. Networking and Determinism

PCAM-24 is inherently network-friendly. * Replication: Transmits Action ID + Phase + Elasticity State. * Prediction: Clients predict by advancing phase. * Reconciliation: Snap to authoritative phase (no complex time rewinding).

6. Benefits

Why use PCAM-24 v2.0?

  • Consistency: All systems share a single semantic clock.
  • Determinism: Eliminates floating-point drift and frame-rate dependence.
  • Expressivity: Overlays and elasticity handle complex modern gameplay.
  • Authorability: Designers reason in stages and intent, not milliseconds.

7. Conclusion

PCAM-24 reframes interactive simulation timing from a question of when to a question of what stage. It is not an optimization of existing timing systems. It is a replacement of their underlying assumption.

Autonomy, Engineered.