diff --git a/packages/server/tests/game-manager.test.ts b/packages/server/tests/game-manager.test.ts
new file mode 100644
index 0000000..f37307e
--- /dev/null
+++ b/packages/server/tests/game-manager.test.ts
@@ -0,0 +1,159 @@
+import { describe, it, expect, beforeEach } from "vitest"
+import { GameManager } from "../src/games/game-manager"
+
+describe("GameManager", () => {
+	let gm: GameManager
+
+	beforeEach(() => {
+		gm = new GameManager()
+	})
+
+	describe("lineup", () => {
+		it("returns the ESC 2026 lineup", () => {
+			const lineup = gm.getLineup()
+			expect(lineup.year).toBe(2026)
+			expect(lineup.countries.length).toBeGreaterThan(20)
+			expect(lineup.countries[0]).toHaveProperty("code")
+			expect(lineup.countries[0]).toHaveProperty("name")
+		})
+
+		it("validates country codes", () => {
+			expect(gm.isValidCountry("DE")).toBe(true)
+			expect(gm.isValidCountry("XX")).toBe(false)
+		})
+	})
+
+	describe("predictions", () => {
+		it("accepts a valid prediction", () => {
+			const result = gm.submitPrediction("p1", "SE", ["DE", "IT", "FR"], "GB")
+			expect(result).toEqual({ success: true })
+			expect(gm.getPrediction("p1")).toEqual({
+				playerId: "p1",
+				predictedWinner: "SE",
+				top3: ["DE", "IT", "FR"],
+				nulPointsPick: "GB",
+			})
+		})
+
+		it("rejects prediction with invalid country", () => {
+			const result = gm.submitPrediction("p1", "XX", ["DE", "IT", "FR"], "GB")
+			expect(result).toEqual({ error: "Invalid country: XX" })
+		})
+
+		it("rejects winner in top 3", () => {
+			const result = gm.submitPrediction("p1", "SE", ["SE", "IT", "FR"], "GB")
+			expect(result).toEqual({ error: "Winner cannot also be in top 3" })
+		})
+
+		it("rejects duplicate top 3", () => {
+			const result = gm.submitPrediction("p1", "SE", ["DE", "DE", "FR"], "GB")
+			expect(result).toEqual({ error: "Top 3 must be unique countries" })
+		})
+
+		it("allows overwriting a prediction", () => {
+			gm.submitPrediction("p1", "SE", ["DE", "IT", "FR"], "GB")
+			gm.submitPrediction("p1", "NO", ["DE", "IT", "FR"], "GB")
+			expect(gm.getPrediction("p1")?.predictedWinner).toBe("NO")
+		})
+
+		it("rejects prediction when locked", () => {
+			gm.lockPredictions()
+			const result = gm.submitPrediction("p1", "SE", ["DE", "IT", "FR"], "GB")
+			expect(result).toEqual({ error: "Predictions are locked" })
+		})
+	})
+
+	describe("dishes", () => {
+		it("adds a dish", () => {
+			const result = gm.addDish("Köttbullar", "SE")
+			expect("dish" in result).toBe(true)
+			if ("dish" in result) {
+				expect(result.dish.name).toBe("Köttbullar")
+				expect(result.dish.correctCountry).toBe("SE")
+				expect(result.dish.revealed).toBe(false)
+			}
+		})
+
+		it("rejects dish with invalid country", () => {
+			const result = gm.addDish("Mystery", "XX")
+			expect(result).toEqual({ error: "Invalid country: XX" })
+		})
+
+		it("accepts a dish guess", () => {
+			const addResult = gm.addDish("Köttbullar", "SE")
+			if (!("dish" in addResult)) throw new Error("unexpected")
+			const result = gm.submitDishGuess("p1", addResult.dish.id, "SE")
+			expect(result).toEqual({ success: true })
+		})
+
+		it("rejects guess for nonexistent dish", () => {
+			const result = gm.submitDishGuess("p1", "fake-id", "SE")
+			expect(result).toEqual({ error: "Dish not found" })
+		})
+
+		it("rejects guess after reveal", () => {
+			const addResult = gm.addDish("Köttbullar", "SE")
+			if (!("dish" in addResult)) throw new Error("unexpected")
+			gm.revealDishes()
+			const result = gm.submitDishGuess("p1", addResult.dish.id, "SE")
+			expect(result).toEqual({ error: "Dish already revealed" })
+		})
+
+		it("replaces an existing guess for the same dish", () => {
+			const addResult = gm.addDish("Köttbullar", "SE")
+			if (!("dish" in addResult)) throw new Error("unexpected")
+			gm.submitDishGuess("p1", addResult.dish.id, "DE")
+			gm.submitDishGuess("p1", addResult.dish.id, "SE")
+			const guesses = gm.getDishGuesses("p1")
+			expect(guesses).toHaveLength(1)
+			expect(guesses[0]?.guessedCountry).toBe("SE")
+		})
+
+		it("reveals dishes and produces results", () => {
+			const addResult = gm.addDish("Köttbullar", "SE")
+			if (!("dish" in addResult)) throw new Error("unexpected")
+			gm.submitDishGuess("p1", addResult.dish.id, "SE")
+			gm.submitDishGuess("p2", addResult.dish.id, "DE")
+			gm.revealDishes()
+
+			const lookup = new Map([
+				["p1", "Alice"],
+				["p2", "Bob"],
+			])
+			const results = gm.getDishResults(lookup)
+			expect(results).toHaveLength(1)
+			expect(results[0]?.guesses).toHaveLength(2)
+
+			const aliceGuess = results[0]?.guesses.find((g) => g.playerId === "p1")
+			expect(aliceGuess?.correct).toBe(true)
+
+			const bobGuess = results[0]?.guesses.find((g) => g.playerId === "p2")
+			expect(bobGuess?.correct).toBe(false)
+		})
+	})
+
+	describe("getGameStateForPlayer", () => {
+		it("hides correct country for unrevealed dishes", () => {
+			gm.addDish("Köttbullar", "SE")
+			const lookup = new Map<string, string>()
+			const state = gm.getGameStateForPlayer("p1", lookup)
+			expect(state.dishes[0]?.correctCountry).toBe("")
+		})
+
+		it("shows correct country after reveal", () => {
+			gm.addDish("Köttbullar", "SE")
+			gm.revealDishes()
+			const lookup = new Map<string, string>()
+			const state = gm.getGameStateForPlayer("p1", lookup)
+			expect(state.dishes[0]?.correctCountry).toBe("SE")
+		})
+
+		it("includes only the requesting player's prediction", () => {
+			gm.submitPrediction("p1", "SE", ["DE", "IT", "FR"], "GB")
+			gm.submitPrediction("p2", "NO", ["DE", "IT", "FR"], "GB")
+			const lookup = new Map<string, string>()
+			const state = gm.getGameStateForPlayer("p1", lookup)
+			expect(state.myPrediction?.predictedWinner).toBe("SE")
+		})
+	})
+})