[SilentSoul]

pawn Код:

public OnPlayerTakeDamage(playerid, issuerid, Float: amount, weaponid)
{
    if(issuerid != INVALID_PLAYER_ID && weaponid == 34) //weaponid == 34 = sniper rifle you can change that
    {
        //Small example if player shooted by sniper from first shoot he will die , you can edit that
        SetPlayerHealth(playerid, 0.0); //and here you can edit the damage you want
    }
    return 1;
}