use rolls[name]

DiceRoll.js

 ygopro.ctos_follow_before('CHAT', false, async function (buffer, info, client, server, datas) {
-    var room = ROOM_all[client.rid];
+	var room = ROOM_all[client.rid];
+	if (room.rolls == undefined)
+	{
+		room.rolls = new Object();
+	}
     var msg = _.trim(info.msg);
     if (msg.substring(0, 5) != "/roll") {
         return;
@@ -28,13 +32,14 @@ ygopro.ctos_follow_before('CHAT', false, async function (buffer, info, client, s
     {
         result += Math.floor(Math.random()*dicemax) + 1;
 	}
-	var message = client.name + "投掷" + dicenum + "d" + dicemax + "并掷出了" + result + "点";
+	var name = client.name;
+	var message = name + "投掷" + dicenum + "d" + dicemax + "并掷出了" + result + "点";
 	log.warn(message);
-	if (client.roll == undefined)
+	if (room.rolls[name] == undefined)
 	{
 		if (dicenum == 1 || dicemax == 100)
 		{
-			client.roll = result;
+			room.rolls[name]  = result;
 			ygopro.stoc_send_chat_to_room(room, message, ygopro.constants.COLORS.YELLOW);
 		}
 		else
@@ -44,7 +49,7 @@ ygopro.ctos_follow_before('CHAT', false, async function (buffer, info, client, s
 	}
 	else
 	{
-		message = message + ";其在本房间内的首次1d100投掷为" + client.roll + "点";
+		message = message + ";首次1d100投掷为" + room.rolls[name] + "点";
 		ygopro.stoc_send_chat_to_room(room, message, ygopro.constants.COLORS.BABYBLUE);
 	}
     return true;