1 files changed, 35 insertions, 0 deletions
diff --git a/internal/casino/craps_simplified_test.go b/internal/casino/craps_simplified_test.go
new file mode 100644
index 0000000..e36bc2d
--- /dev/null
+++ b/internal/casino/craps_simplified_test.go
@@ -0,0 +1,35 @@
+package casino
+
+import "testing"
+
+func TestSimplifiedCrapsAll36SettlementsAndHouseEdge(t *testing.T) {
+	// Total returns for a one-credit wager, including the winning stake.
+	returns := [13]int{2: 4, 3: 2, 4: 2, 10: 3, 11: 3, 12: 6}
+	totalReturned, wins := 0, 0
+	for a := 1; a <= 6; a++ {
+		for b := 1; b <= 6; b++ {
+			tb := variantFixture("simplified")
+			tb.join("a")
+			w := &testWallet{chips: 100}
+			tb.bet("a", "pass", 1, w)
+			want := returns[a+b]
+			for _, row := range tb.projectionFor(tb.players.get("a")) {
+				if row.Total == a+b && row.Net != want-1 {
+					t.Fatalf("preview for %d+%d: got %d, want %d", a, b, row.Net, want-1)
+				}
+			}
+			tb.resolveRoll(a, b)
+			if w.paid != want || len(w.open) != 0 || tb.players.get("a").HasBet || tb.point != 0 {
+				t.Fatalf("roll %d+%d: paid %d, want %d; open %v, point %d", a, b, w.paid, want, w.open, tb.point)
+			}
+			totalReturned += w.paid
+			if w.paid > 0 {
+				wins++
+			}
+		}
+	}
+	// 36 credits wagered, 35 returned: house edge exactly 1/36 = 2.777...%.
+	if totalReturned != 35 || wins != 12 {
+		t.Fatalf("all 36 rolls: returned %d, wins %d", totalReturned, wins)
+	}
+}