Im trying to make gamble plugin that uses scrap you have in your inventory. Im not sure how i could add it that you would need to type amount of scrap to gamble. Something like int amount = 1; <- command changes amount of scrap somehow. 

Chat command hook have 3 parameters - BasePlayer, string and string array, third is arguments (all whats typed after the command itself, separated by spaces), you need to parse arguments by int.TryParse.

Thank you, i will look into that.

could you give me little example?

[ChatCommand("gamble")]
        private void CmdGamble(BasePlayer player, string command, string[] args)
        {
            if(args.Length < 1)
            {
                player.ChatMessage("Wrong command usage");
                return;
            }

            var amount = default(int);

            if(!int.TryParse(args[0], out amount))
            {
                player.ChatMessage("Wrong command usage");
                return;
            }

            //at this moment amount is parsed, do whatever you want with it.
        }