diff --git a/docs/plans/2026-04-11-roadmap.md b/docs/plans/2026-04-11-roadmap.md
index b6f0eac..00f3b23 100644
--- a/docs/plans/2026-04-11-roadmap.md
+++ b/docs/plans/2026-04-11-roadmap.md
@@ -31,6 +31,7 @@
 | A.1 | Streaming landblock loader — runtime-configurable visible window (default 5×5, `ACDREAM_STREAM_RADIUS`), camera-centered offline / player-centered live, hysteresis-based unloads, pending-spawn list for late CreateObject events | Live ✓ |
 | A.2 | Frustum culling — per-landblock AABB test (Gribb-Hartmann), terrain + static-mesh renderers skip culled landblocks, perf overlay in window title | Visual ✓ |
 | A.3 | Background net receive thread — dedicated daemon thread buffers UDP into Channel, render thread drains | Visual ✓ |
+| B.3 | Physics collision engine — TerrainSurface (heightmap Z), CellSurface (indoor floor polygon projection), PhysicsEngine (resolver with step-height + cell transitions). Populated from streaming pipeline. | Tests ✓ |
 
 Plus polish that doesn't get its own phase number:
 - FlyCamera default speed lowered + Shift-to-boost
@@ -66,9 +67,9 @@ Plus polish that doesn't get its own phase number:
 **Goal:** actually play the game — walk the character on the server, click NPCs, pick up items, chat, basic combat loop.
 
 **Sub-pieces:**
-- **B.1 — Outbound ack pump.** Background timer that sends sequence acks every ~250ms. Without this the server drops idle clients after ~30s regardless of any other activity.
-- **B.2 — `PlayerAutonomousMove` outbound.** Wire WASD + camera state (or a dedicated player-controlled movement mode) to an outbound movement message so the server's view of the character matches ours.
-- **B.3 — Collision against terrain.** Required for the server to accept moves at all — ACE rejects client positions that are inside geometry or in disallowed Z ranges. Minimum viable: sample the terrain heightmap beneath the player and clamp Z. Proper: walk the `CellBSP` / `PhysicsBSP` we already parse.
+- **✓ SHIPPED — B.1 — Outbound ack pump.** Shipped as Phase 4.9 — per-packet ACK_SEQUENCE, not periodic. Server no longer drops idle clients.
+- **B.2 — `PlayerAutonomousMove` outbound.** Wire WASD + camera state (toggle between fly mode and player mode) to an outbound movement message so the server's view of the character matches ours. Requires B.3.
+- **✓ SHIPPED — B.3 — Physics collision engine.** TerrainSurface (heightmap bilinear Z), CellSurface (indoor floor polygon projection via barycentric interpolation), PhysicsEngine (top-level resolver with step-height enforcement, outdoor↔indoor cell transitions, gravity reporting). Populated from streaming pipeline. 16 unit tests with fake data. Spec: `docs/superpowers/specs/2026-04-12-physics-collision-engine-design.md`.
 - **B.4 — `Use` / `UseWithTarget` / `PickUp`.** Outbound interaction messages. Drives opening doors, looting, talking to vendors.
 - **B.5 — Chat.** `SendTell`, `SendChat` outbound + receive/display inbound (display side depends on Phase D.1).