Z-G is a combination miniatures wargame/collectible card game. The miniatures, which represent arena combat robots, are actually 5" action figures with 14 points of articulation and 8 pieces of removable armor. Each piece of armor has a corresponding collectible card giving its statistics and special powers. Each basic set includes a fixed 10 card set (1 card per piece of equipment, including the figure itself, plus a character card)
The game is played in rounds, which start with all players choosing which 3 pieces of equipment to use this round. Each piece of equipment also has an impulse rating, and whoever has the highest impulse goes first. Players then use their cards to move their figure a number of card lengths and/or use attacks based on a color-matching system on the ends of each card. If your attack is successful, a piece of your opponent's armor is destroyed (and so is its corresponding card).
One of the more innovative parts in all this is that the actual figure poses have bearing on gameplay. Movement points must be used to enter a stance, and each stance has certain advantages and disadvantages (Except lying down, which is universally bad)
Z-G was first shown publicly for sale and demonstration at Origins 2001 in Columbus, Ohio, with the subtitle "Citizen." Although planned as the first set in a series of sets, "Citizen Z-G" was ultimately the only published set.