[Betamaster]

You actually need to do a combination of what people have previously suggested.

Create your 3D labels (Create3DTextLabel) in OnGameModeInit:

pawn Code:

label1 = Create3DTextLabel("HEAD ADMINISTRATOR",0x7CFC0075,30.0,40.0,50.0,40.0,0);
label2 = Create3DTextLabel("ADMINISTRATOR",0x7CFC0075,30.0,40.0,50.0,40.0,0);
label3 = Create3DTextLabel("MODERATOR",0x7CFC0075,30.0,40.0,50.0,40.0,0);
label4 = Create3DTextLabel("DONATOR",0x7CFC0075,30.0,40.0,50.0,40.0,0);

Then once the player is logged in, presumably in OnPlayerConnect (or whenever IsPlayerDAdminByDeadly[playerid][Level] and IsPlayerDAdminByDeadly[playerid][pVip] will return correct values), attach the label to the player.

pawn Code:

switch(IsPlayerDAdminByDeadly[playerid][Level]) {
    case 3: Attach3DTextLabelToPlayer(label1, playerid, 0.0, 0.0, 0.7);
    case 2: Attach3DTextLabelToPlayer(label2, playerid, 0.0, 0.0, 0.7);
    case 1: Attach3DTextLabelToPlayer(label3, playerid, 0.0, 0.0, 0.7);
    default: {
        if(IsPlayerDAdminByDeadly[playerid][pVip] == 0) {
            Attach3DTextLabelToPlayer(label4, playerid, 0.0, 0.0, 0.7);
        }
    }
}