DO YOU WANT A LOLLIPOP, BOY?
Ahem. I suppose you are playing a custom party in multiplayer.
-if you want to get a NPC, just go to the Pocket Plane and summon them;
-if you want to add another custom character, open character arbitration (button above rest), click Modify Characters, and create a new one as you created the existing three.
NOTE:
If you have moved your game to Singleplayer Game folder, you'll need to move it back into Multiplayer folder.
If you haven't, then consider doing it (after adding the fourth character, of course):
-save your multiplayer game;
-locate your Baldur's Gate installation folder and open it;
-open "MPsave" folder, locate the saved game, and move it into "Save" folder;
-back in the game, start singleplayer and load the save.
Hope this helps, kid.
