[Abreezy]

pawn Код:

CMD:rob(playerid, params[])
{
    new string[128], pID;
    if(sscanf(params, "u", pID)) return SendClientMessage(playerid, -1, "Correct usage for command is: /rob playerid");
    
    new cash = GetPlayerMoney(pID);
    new Float:steal =  cash * 0.10;
    
    format(string, sizeof(string), "You have stolen %d from ID %i", floatround(steal), pID);
    SendClientMessage(playerid, -1, string);
    
    GivePlayerMoney(playerid, floatround(steal));
    return 1;
}

This is untested, should be what you wanted, let me know if any errors or whatever.

You need ZCMD and SSCANF btw.