[Lordzy]

By using SetPlayerTeam, I think it works as an anti-teamkill too. Or else, you could try something like this:

pawn Код:

new team1[MAX_PLAYERS], team2[MAX_PLAYERS]; //Creating two team global variables.

public OnPlayerTakeDamage(playerid, issueried, Float:amount, weaponid)
{
  if(Team1[issuerid] == 1 && Team1[playerid] == 1)  //If issuer and the player is in same team.
  {
    new Float:hp[MAX_PLAYERS]; 
    GetPlayerHealth(playerid, hp[playerid]);
    SetPlayerHealth(playerid, hp[playerid]); //So, here it gives balance and the player won't die.
   }
  return 1;
} 
//I believe this could work.