As a first-person shooter, the gameplay of Duke Nukem 3D involves moving through levels presented from the protagonist's point of view, shooting enemies on the way.
The environment of Duke Nukem 3D is highly destructible; most props can be destroyed by the player.
The game includes a range of lethal weapons, some of which, even today, are still unique to the Duke Nukem series. They range from Duke's "Mighty Foot", a basic melee attack, to a pistol, a Chain gun (similar in design to the Nordenfelt gun), pipe bombs, freeze- and shrink-rays, laser trip mines and even a very powerful rapid fire rocket launcher called the "Devastator".
Aside from weapons, Nukem's inventory also includes a series of items that can be picked up during play. A portable medkit allows players to heal themselves whenever they choose to. Steroids speed up player movement making transit through hostile territory easier, as well as instantly reversing the effects of the shrinker. Nightvision goggles allow players to see enemies in the dark. The "HoloDuke" device projects a hologram of Duke that can be used to distract enemies. Protective boots allow the player to cross dangerously hot or toxic terrain. Where progress requires more aquatic legwork, scuba gear (an aqua-lung) allows the player to take longer trips away from air. Perhaps most impressively, Duke's trademark jetpack allows the player to range fully in 3D, often to reach hidden weapons caches or extra health.
Duke Nukem 3D features multiplayer. In 1996 at the time of its release, Internet-based gaming was just beginning. Duke Nukem 3D did not support the TCP/IP client/server model, instead basing its network play on the IPX LAN, modem or serial cable. Duke Nukem 3D players often either battled modem-to-modem, using the $20.00 IPX network utility Kali or the Total Entertainment Network (TEN) online pay service. Kali allowed users to connect to a chat room to host and join games. The Total Entertainment Network featured hundreds of Duke 3D players online at any given time and players had to pay a monthly fee for it (originally $5.00, gradually increased to $20.00). In 1996 TEN hosted a first of its kind, nationally participated in "online tournament" rewarding the champions with cash and prizes sparking an immediate surge in online gaming. Some of the first prizes were $500 cash and a lifetime membership to the service. The only Duke tournament was won by one of the first cyber athletes, Christopher S Carpentier, aka "Creamator", who battled over 14 thousand entries to claim the title of "One True Duke!" Most of these newly declared cyber athletes later went on to the PGL "Professional Gamers League" after TEN converted its business model to Pogo.
Duke's levels were often used as the battlegrounds for these encounters and users were even able to create their own levels (or maps) via the in-game build engine. The game also features co-operative play (co-op) which allows players to complete the story based single player mode together. In the Atomic version, a new game play mode was introduced: Duke Tag, a "capture the flag" style mode.
Duke Nukem multiplayer continues to exist through services such as YANG and Dukester X, thanks to fan made ports such as eDuke32 and xDuke.
