new rand = random(10); // How many cases


                switch(rand)
                {
                    case 0, 3, 5, 7: //Case number = a chance 
                    {
                        SendClientMessage(playerid, W, "You robbed the bank!" );
                    }
                    case 1, 4, 6, 8: // The more the case numbers the bigger the chance.
                    {
                                  SendClientMessage(playerid, W, "You have been caught!" );

public OnPlayerPickUpPickup(playerid, pickupid)
{
    if(pickupid == myrobpickup) // So your pick up should be defined as what you want it to be. I used myrobpickup as an example
    {
    
    new rand = random(10);


    switch(rand)
    {
        case 0, 3, 5, 7:
        {
            SendClientMessage(playerid, WHITE, "You have robbed the bank!");
        }
        case 1, 4, 6, 8:
        {
            SendClientMessage(playerid, WHITE, "You got caught");