[The_Moddler]

pawn Code:

if(!strcmp("/try", cmdtext, true, 5))
{
    new name[25], string[64];
     GetPlayerName(playerid, name, 25);
      switch(random(3))
       {
        case 0:
         {
             format(string, 64, "%s Tries to: %s and succeeds", name);
              SendClientMessage(playerid, COLOR_PURPLE, string);
          }
           case 2:
           {
               format(string, 64, "%s Tries to %s but fails", name);
            SendClientMessage(playerid, COLOR_PURPLE, str1);
           }
           case 3:
           {
               format(string, 64, "%s Tries to %s but fails", name);
            SendClientMessage(playerid, COLOR_PURPLE, str1);
           }
    }
     return 1;
}

1st- Watch out your string sizes.. max player name is 24+null character = 25.
2nd- Don't use sizeof it uses prossesor..
3nd- You didn't made a case, random 3 has 0, 1 or 2.