PCAM-24: A Phase-Centric Action Model (v2.0)
For Deterministic Synchronous Simulation
Abstract
This paper introduces PCAM-24 v2.0 (Phase-Centric Action Model), an upgraded simulation model where discrete phase—rather than continuous time—is the authoritative coordinate for action progression, interaction adjudication, and cross-system synchronization. V2.0 evolves the model to handle high-fidelity combat through Layered Windows and Phase Elasticity.
By elevating phase to a first-class primitive, PCAM-24 eliminates timing inference between subsystems, simplifies deterministic networking, and provides a shared semantic language for animation, combat, and AI. The result is a system that is deterministic by construction and perfectly synchronized.
1. Introduction
Interactive simulations traditionally coordinate multiple subsystems that operate on disparate notions of time. This fragmentation produces systemic problems: desynchronization between visuals and outcomes, frame-rate dependence, and ambiguous interaction adjudication.
PCAM-24 addresses these issues by replacing time with discrete phase. Rather than asking "when did something happen?", the model 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: $\(\text{Phase} \in \mathbb{Z}_{24} = \{0, 1, \dots, 23\}\)$ Phase advances discretely and wraps modulo 24. It is the sole authoritative coordinate for all gameplay-relevant logic.
2.2 Layered Windows (v2.0)
In v2.0, action properties are expressed as Layered Windows. Unlike v1.0's flat, non-overlapping windows, layering allows multiple properties to coexist at the same phase. For example, a "Heavy Attack" may be simultaneously ACTIVE (dealing damage) and MITIGATING (absorbing hits with armor).
2.3 Phase Elasticity (v2.0)
V2.0 introduces Elasticity, allowing the phase cycle to "bend" while remaining discrete and monotonic: - STALL: Holding a phase for multiple simulation ticks (e.g., hit-stop on impact). - SKIP: Jumping forward in the cycle (e.g., action canceling). - NEST: Entering a sub-phase cycle for complex, multi-stage actions.
3. Interaction Adjudication
3.1 Deterministic Precedence Matrix
Cross-entity interactions are resolved by evaluating overlapping windows through a fixed precedence matrix: 1. VOID (Invulnerability) 2. COUNTER (Parry/Deflect) 3. MITIGATE (Armor/Block) 4. IMPACT (Active Hit)
This ensures that outcomes are always deterministic, fair, and consistent across different platforms and network conditions.
4. Subsystem Subscription
Subsystems (Animation, AI, VFX, Audio) subscribe to the authoritative phase. They do not advance or reinterpret it. This ensures that the visual representation (e.g., a sword swing) is always a faithful view of the underlying simulation state.
5. Networking and Determinism
PCAM-24 is inherently network-friendly because it replicates phase, not time. - Replication transmits action identifiers and phase values. - Clients predict locally by advancing phase using the same rules. - Reconciliation is performed by snapping phase to authoritative values, avoiding complex time-warping artifacts.
6. Conclusion
PCAM-24 v2.0 reframes interactive simulation as a sequence of semantic stages rather than a duration of milliseconds. By introducing Layered Windows and Phase Elasticity, it provides the robust substrate required for high-fidelity interactive systems where synchronization is non-negotiable.
Autonomy, Engineered.
Greyforge Labs