# 0010: Mass Entity For Crowds

Status: Accepted

Date: 2026-05-23

## Context

Hitman-class sandbox maps require hundreds of civilians with perception,
schedules, reactions, and replication boundaries. Actor-only crowds would put
unnecessary pressure on ticking, memory, and replication.

## Decision

V4 uses Unreal Mass Entity as the default dense-crowd runtime. Actor facades are
reserved for characters currently interacting with players, cinematics, or
high-fidelity combat.

## Consequences

- Crowd schedules and perception data must support Mass fragments.
- Asset and data linting must reject crowd content that bypasses the Mass
  pipeline without an explicit exemption.
- Performance tests must cover 400-NPC sandbox density.