"The Twilight: 2000 Ref's Screen is fully usable with Twilight: 2000, Merc: 2000 and the other products in the Twilight: 2000 system.... [The tri-fold screen] comes wrapped around a 16-page booklet containing new D20 game mechanics, consolidated small arms and heavy weapons listings (From both Small Arms of the World and Heavy Weapons Handbook), rules extensions to character generation, combat (including a system for skill-based fully automatic fire), still more charts (in a 4-page pull-out section), and optional rules including (among other things) the first treatment of enhanced damage rounds (such as hollow points and mercury loads) in the Twilight: 2000 system.