About Duke Nukem 3D

First Person Shooters prior to Duke 3d didn't feature "realistic" real world locations. Things that Duke 3d did first include: televisions that show different programmes; closed circuit security cameras that let you see other areas of the level than the bit you're in; working subway trains that take you across "town"; strip bars/clubs; breakable glass/destroyable furniture/mirrors that you can see your own reflection in; triggered set pieces such as earthquakes that can destroy the architecture around the player; and working toilets that you can use to gain extra health. These things were quite revolutionary at the time, and the level design in later games of the genre (such as Half Life, Deus Ex, Soldier Of Fortune, and even aspects of Doom 3) show signs of its ground breaking influence. It could be argued that this organic approach to level design would have come about anyway as a direct result of increasingly better technology... but nevertheless, Duke 3d was there first.