[Threshold]

If you are using 0.3z:

pawn Код:

public OnPlayerTakeDamage(playerid, issuerid, Float:amount, weaponid, bodypart)
{
    if(issuerid != INVALID_PLAYER_ID && issuerid != playerid)
    {
        PlayerInfo[issuerid][Experience] += amount; //This is an example, you may have something other than PlayerInfo[issuerid][Experience] to define your experience level.
        //NOTE: The person HITTING the player is 'issuerid', not 'playerid'.
    }
    return 1;
}

Versions earlier than 0.3z:

pawn Код:

public OnPlayerTakeDamage(playerid, issuerid, Float:amount, weaponid)
{
    if(issuerid != INVALID_PLAYER_ID && issuerid != playerid)
    {
        PlayerInfo[issuerid][Experience] += amount; //This is an example, you may have something other than PlayerInfo[issuerid][Experience] to define your experience level.
        //NOTE: The person HITTING the player is 'issuerid', not 'playerid'.
    }
    return 1;
}