diff --git a/pkg/server/game.go b/pkg/server/game.go
index da42e15..cc29c74 100644
--- a/pkg/server/game.go
+++ b/pkg/server/game.go
@@ -666,7 +666,7 @@ func (g *serverGame) handleWin() bool {
 	var reset bool
 	if g.Winner == 1 {
 		winEvent.Player = g.Player1.Name
-		g.Player1.Points = g.Player1.Points + winPoints*g.DoubleValue
+		g.Player1.Points = add8(g.Player1.Points, mul8(winPoints, g.DoubleValue))
 		if g.Player1.Points < g.Points {
 			reset = true
 		} else {
@@ -674,7 +674,7 @@ func (g *serverGame) handleWin() bool {
 		}
 	} else {
 		winEvent.Player = g.Player2.Name
-		g.Player2.Points = g.Player2.Points + winPoints*g.DoubleValue
+		g.Player2.Points = add8(g.Player2.Points, mul8(winPoints, g.DoubleValue))
 		if g.Player2.Points < g.Points {
 			reset = true
 		} else {
diff --git a/pkg/server/server.go b/pkg/server/server.go
index d86992e..86e1042 100644
--- a/pkg/server/server.go
+++ b/pkg/server/server.go
@@ -556,6 +556,31 @@ func RandInt(max int) int {
 	return int(i.Int64())
 }
 
+// add8 adds two int8 values without overflowing.
+func add8(a int8, b int8) int8 {
+	v := a
+	for i := int8(0); i < b; i++ {
+		a++
+		if a < 0 {
+			return 127
+		}
+		v++
+	}
+	return v
+}
+
+// mul8 multiplies two int8 values without overflowing.
+func mul8(a int8, b int8) int8 {
+	var v int8
+	for i := int8(0); i < b; i++ {
+		v = add8(v, a)
+		if v == 127 {
+			return v
+		}
+	}
+	return v
+}
+
 func gnubgPosition(g *bgammon.Game) string {
 	var opponent int8 = 2
 	start := 0
diff --git a/pkg/server/server_command.go b/pkg/server/server_command.go
index 4e24b2e..8207a28 100644
--- a/pkg/server/server_command.go
+++ b/pkg/server/server_command.go
@@ -395,9 +395,11 @@ COMMANDS:
 			}
 
 			points, err := strconv.Atoi(string(gamePoints))
-			if err != nil || points < 1 || points > 99 {
+			if err != nil || points < 1 {
 				sendUsage()
 				continue
+			} else if points > 127 {
+				points = 127
 			}
 
 			// Set default game name.
@@ -614,10 +616,10 @@ COMMANDS:
 
 			var reset bool
 			if clientGame.Winner == 1 {
-				clientGame.Player1.Points = clientGame.Player1.Points + clientGame.DoubleValue
+				clientGame.Player1.Points = add8(clientGame.Player1.Points, clientGame.DoubleValue)
 				reset = clientGame.Player1.Points < clientGame.Points
 			} else {
-				clientGame.Player2.Points = clientGame.Player2.Points + clientGame.DoubleValue
+				clientGame.Player2.Points = add8(clientGame.Player2.Points, clientGame.DoubleValue)
 				reset = clientGame.Player2.Points < clientGame.Points
 			}
 			clientGame.addReplayHeader()