diff --git a/board.go b/board.go
index e288e03..971b646 100644
--- a/board.go
+++ b/board.go
@@ -26,7 +26,11 @@ func (b *Board) GetRow(id int) []*Card {
 }
 
 func (b *Board) GetCard(id int, pos int) *Card {
-	return b.GetRow(id)[pos]
+	if pos >= 0 && pos <= 3 {
+		return b.GetRow(id)[pos]
+	} else {
+		return nil
+	}
 }
 
 func (b *Board) Remove(c *Card) {