diff --git a/src/runtime-three/player-edge-assist.ts b/src/runtime-three/player-edge-assist.ts
new file mode 100644
index 00000000..895920c9
--- /dev/null
+++ b/src/runtime-three/player-edge-assist.ts
@@ -0,0 +1,171 @@
+import type { Vec3 } from "../core/vector";
+
+import type {
+  FirstPersonPlayerShape,
+  PlayerGroundProbeResult
+} from "./player-collision";
+
+const EDGE_ASSIST_FORWARD_PADDING_METERS = 0.12;
+const EDGE_ASSIST_FORWARD_STEPS = 3;
+const EDGE_ASSIST_VERTICAL_STEPS = 6;
+const EDGE_ASSIST_MIN_TOP_OUT_HEIGHT_METERS = 0.04;
+const EDGE_ASSIST_GROUND_PROBE_DISTANCE_METERS = 0.35;
+const VECTOR_EPSILON = 1e-6;
+
+export interface RuntimePlayerEdgeAssistResult {
+  feetPosition: Vec3;
+  lift: number;
+  forwardDistance: number;
+}
+
+function dotVec3(left: Vec3, right: Vec3): number {
+  return left.x * right.x + left.y * right.y + left.z * right.z;
+}
+
+function lengthVec3(vector: Vec3): number {
+  return Math.sqrt(dotVec3(vector, vector));
+}
+
+function normalizePlanarDirection(direction: Vec3): Vec3 | null {
+  const planarDirection = {
+    x: direction.x,
+    y: 0,
+    z: direction.z
+  };
+  const length = lengthVec3(planarDirection);
+
+  if (length <= VECTOR_EPSILON) {
+    return null;
+  }
+
+  return {
+    x: planarDirection.x / length,
+    y: 0,
+    z: planarDirection.z / length
+  };
+}
+
+function getPlayerShapeHorizontalRadius(shape: FirstPersonPlayerShape): number {
+  switch (shape.mode) {
+    case "capsule":
+      return shape.radius;
+    case "box":
+      return Math.max(shape.size.x, shape.size.z) * 0.5;
+    case "none":
+      return 0;
+  }
+}
+
+export function shouldAttemptPlayerEdgeAssist(options: {
+  enabled: boolean;
+  pushToTopHeight: number;
+  inputMagnitude: number;
+  requestedPlanarSpeed: number;
+  planarSpeed: number;
+  collisionCount: number;
+  airborne: boolean;
+}): boolean {
+  return (
+    options.enabled &&
+    options.pushToTopHeight >= EDGE_ASSIST_MIN_TOP_OUT_HEIGHT_METERS &&
+    options.airborne &&
+    options.inputMagnitude > 0 &&
+    options.collisionCount > 0 &&
+    options.requestedPlanarSpeed > 0 &&
+    options.planarSpeed < options.requestedPlanarSpeed * 0.55
+  );
+}
+
+export function resolvePlayerEdgeAssistTopOut(options: {
+  feetPosition: Vec3;
+  shape: FirstPersonPlayerShape;
+  direction: Vec3;
+  pushToTopHeight: number;
+  canOccupyShape(feetPosition: Vec3, shape: FirstPersonPlayerShape): boolean;
+  probeGround(
+    feetPosition: Vec3,
+    shape: FirstPersonPlayerShape,
+    maxDistance: number
+  ): PlayerGroundProbeResult;
+}): RuntimePlayerEdgeAssistResult | null {
+  if (
+    options.shape.mode === "none" ||
+    options.pushToTopHeight < EDGE_ASSIST_MIN_TOP_OUT_HEIGHT_METERS
+  ) {
+    return null;
+  }
+
+  const direction = normalizePlanarDirection(options.direction);
+
+  if (direction === null) {
+    return null;
+  }
+
+  const horizontalRadius = getPlayerShapeHorizontalRadius(options.shape);
+  const maxForwardDistance =
+    horizontalRadius + EDGE_ASSIST_FORWARD_PADDING_METERS;
+  const maxGroundProbeDistance = Math.max(
+    EDGE_ASSIST_GROUND_PROBE_DISTANCE_METERS,
+    options.pushToTopHeight + EDGE_ASSIST_MIN_TOP_OUT_HEIGHT_METERS
+  );
+
+  for (
+    let verticalStep = 1;
+    verticalStep <= EDGE_ASSIST_VERTICAL_STEPS;
+    verticalStep += 1
+  ) {
+    const lift =
+      (options.pushToTopHeight * verticalStep) / EDGE_ASSIST_VERTICAL_STEPS;
+
+    for (
+      let forwardStep = 1;
+      forwardStep <= EDGE_ASSIST_FORWARD_STEPS;
+      forwardStep += 1
+    ) {
+      const forwardDistance =
+        (maxForwardDistance * forwardStep) / EDGE_ASSIST_FORWARD_STEPS;
+      const raisedCandidate = {
+        x: options.feetPosition.x + direction.x * forwardDistance,
+        y: options.feetPosition.y + lift,
+        z: options.feetPosition.z + direction.z * forwardDistance
+      };
+
+      if (!options.canOccupyShape(raisedCandidate, options.shape)) {
+        continue;
+      }
+
+      const ground = options.probeGround(
+        raisedCandidate,
+        options.shape,
+        maxGroundProbeDistance
+      );
+
+      if (!ground.grounded || ground.distance === null) {
+        continue;
+      }
+
+      const groundedCandidate = {
+        x: raisedCandidate.x,
+        y: raisedCandidate.y - ground.distance,
+        z: raisedCandidate.z
+      };
+      const topOutHeight = groundedCandidate.y - options.feetPosition.y;
+
+      if (
+        topOutHeight < EDGE_ASSIST_MIN_TOP_OUT_HEIGHT_METERS ||
+        topOutHeight > options.pushToTopHeight + VECTOR_EPSILON ||
+        !options.canOccupyShape(groundedCandidate, options.shape)
+      ) {
+        continue;
+      }
+
+      return {
+        feetPosition: groundedCandidate,
+        lift: topOutHeight,
+        forwardDistance
+      };
+    }
+  }
+
+  return null;
+}