diff --git a/src/server/game/mod/order/OrderFunc.go b/src/server/game/mod/order/OrderFunc.go
index 99803a5d..dab8967c 100644
--- a/src/server/game/mod/order/OrderFunc.go
+++ b/src/server/game/mod/order/OrderFunc.go
@@ -136,6 +136,9 @@ func getChessLv(Min, Max, Diff int) int {
 	case diff_high:
 		Start = Min + (Max-Min+1)/3*2
 	}
+	Start = max(Min, Start)
+	End = max(Start, End)
+	End = min(Max, End)
 	return GoUtil.RandNum(Start, End)
 }