diff --git a/src/die.js b/src/die.js
new file mode 100644
index 0000000..b766519
--- /dev/null
+++ b/src/die.js
@@ -0,0 +1,3 @@
+export function rollDie() {
+  return Math.floor(Math.random() * 6) + 1;
+}
diff --git a/src/die.test.js b/src/die.test.js
new file mode 100644
index 0000000..65db58b
--- /dev/null
+++ b/src/die.test.js
@@ -0,0 +1,12 @@
+import { describe, expect, test } from "bun:test";
+import { rollDie } from "./die.js";
+
+describe("rollDie", () => {
+  test("returns a number between 1 and 6", () => {
+    for (let i = 0; i < 100; i++) {
+      const result = rollDie();
+      expect(result).toBeGreaterThanOrEqual(1);
+      expect(result).toBeLessThanOrEqual(6);
+    }
+  });
+});
diff --git a/src/enemies.js b/src/enemies.js
index 7ac88ec..ce17e03 100644
--- a/src/enemies.js
+++ b/src/enemies.js
@@ -3,3 +3,18 @@ import enemyDb from "../data/enemies.json";
 export function getEnemy(id) {
   return enemyDb[id];
 }
+
+export function resolveEnemyAction(enemy, dieResult, trackPosition) {
+  if (enemy.actionType === "single") {
+    return enemy.actions["1"];
+  }
+  if (enemy.actionType === "die") {
+    return enemy.actions[String(dieResult)];
+  }
+  if (enemy.actionType === "cube") {
+    const track = enemy.actionTrack;
+    const pos = Math.min(trackPosition, track.length - 1);
+    return track[pos];
+  }
+  return { intent: "unknown", effects: [] };
+}
diff --git a/src/enemies.test.js b/src/enemies.test.js
new file mode 100644
index 0000000..4b869df
--- /dev/null
+++ b/src/enemies.test.js
@@ -0,0 +1,19 @@
+import { describe, expect, test } from "bun:test";
+import { getEnemy, resolveEnemyAction } from "./enemies.js";
+
+describe("getEnemy", () => {
+  test("returns enemy by id", () => {
+    const enemy = getEnemy("jaw_worm");
+    expect(enemy.name).toBe("Jaw Worm");
+    expect(enemy.hp).toBeGreaterThan(0);
+  });
+});
+
+describe("resolveEnemyAction", () => {
+  test("die action returns effects for given roll", () => {
+    const enemy = getEnemy("jaw_worm");
+    const action = resolveEnemyAction(enemy, 1, 0);
+    expect(action.effects).toBeDefined();
+    expect(action.effects.length).toBeGreaterThan(0);
+  });
+});