# E2.M4 — ProgressionPacingControls

## Summary

| Field | Value |
|--------|--------|
| **Module ID** | E2.M4 |
| **Epic** | [Epic 2 — Classless Progression](../epics/epic_02_classless_progression.md) |
| **Stage target** | Pre-production |
| **Status** | Planned (see [dependency register](module_dependency_register.md)) |

## Purpose

Tuning knobs for progression velocity and catch-up policy, informed by KPIs from [E9.M2](E9_M2_KpiDashboardsAndAlerting.md).

## Responsibilities

- Apply `XpModifierProfile`, `CatchUpRule`, and `PacingPolicy` without breaking skill-ID integrity from [E2.M1](E2_M1_SkillDefinitionRegistry.md) / [E2.M2](E2_M2_XpAwardAndLevelEngine.md).

## Key contracts

| Contract | Role |
|----------|------|
| `XpModifierProfile` | Multipliers or bands per cohort. |
| `CatchUpRule` | Acceleration for lapsed or new players. |
| `PacingPolicy` | Named policy bundles for ops toggles. |

## Module dependencies

- **E2.M2** — XpAwardAndLevelEngine.
- **E9.M2** — KpiDashboardsAndAlerting.

## Dependents (by design)

- **E9.M3** — LiveBalanceControlPlane (remote tuning).

## Related implementation slices

Epic 2 **Slice 4** — pacing policy toggles for test cohorts where possible without full redeploy.

## Source anchors

- Master plan: [`neon_sprawl_vision.plan.md`](../../../neon_sprawl_vision.plan.md) — Epic 2.
- [Module dependency register](module_dependency_register.md)