diff --git a/docs/plans/2026-04-11-roadmap.md b/docs/plans/2026-04-11-roadmap.md
index 3c915ec..e5cfb5a 100644
--- a/docs/plans/2026-04-11-roadmap.md
+++ b/docs/plans/2026-04-11-roadmap.md
@@ -81,6 +81,7 @@ Plus polish that doesn't get its own phase number:
 - **✓ SHIPPED — A.2 — Frustum culling.** Per-landblock AABB test (Gribb-Hartmann plane extraction + positive-vertex AABB test) in both `TerrainRenderer.Draw` and `StaticMeshRenderer.Draw`. Per-entity culling deferred. LOD deferred to Phase C. Performance overlay in window title shows FPS, frame time, visible/total landblock ratio, entity count, animated count. ~160fps uncapped at 5×5 radius.
 - **✓ SHIPPED — A.3 — Background net receive thread.** Dedicated daemon thread continuously pulls raw UDP datagrams from the kernel buffer into a `Channel<byte[]>`. Render thread's `Tick()` drains the channel. All decode, fragment assembly, ISAAC crypto, event dispatch, and ack-sending remain on the render thread — minimal change that prevents packet drops during frame stalls. Thread starts after `EnterWorld()` completes; `PumpOnce()` during handshake still reads the socket directly.
 - **A.4 — Async dat decoding.** Folded into the streaming worker — it's the worker's read path, not a separate subsystem. Called out here because regressions in dat caching could land on this surface.
+- **A.5 — Two-tier streaming + terrain horizon LOD.** Split `ACDREAM_STREAM_RADIUS` into two: `ACDREAM_TERRAIN_RADIUS` (large, 8-12 cells = 1.5-2.3km) for terrain mesh + `ACDREAM_ENTITY_RADIUS` (small, 2-3 cells, current default) for entities + scenery. Distant landblocks render terrain only — no NPCs, no procedural scenery, no static objects. Tune `SceneLightingUbo`'s `uFogParams` so the far edge fades into sky color (eliminates the hard streaming boundary visible at higher radii). Optional: terrain LOD via mesh decimation for very distant chunks (combine 2×2 landblocks into one decimated mesh; cribs from `references/WorldBuilder/Chorizite.OpenGLSDLBackend/Lib/TerrainRenderManager.cs`). Motivation: at radius=5 today, perf scales from ~810 fps → ~200-300 fps because everything stays full-detail; both retail and WorldBuilder render terrain way out and strip entities/scenery at distance. Enables WB-style horizon visibility. **Estimate: 3-5 days for the radius split + fog tuning; +1 week if terrain LOD is included.** Not yet brainstormed.
 
 **Acceptance:**
 - Walk across 10+ landblocks in any direction, no crashes, no empty voids.