you cant create multiplayer game in 3dgamestudio except if you want something like turn based game, maybe then you can. but FPS, RTS, MMORPG and such stuff you cant create in 3dgs without plugins.
you should consider using the plugins because it's the best solution there is for multiplayer games in 3dgs. i recommend ANet plugin
actually, you can make a fps, but you have to know what is should be created client side and what should be created server-side, with optimal code you can do that, but alos you can't expect optimal-code from first time multiplayer programmer.
