Illuminati: New World Order is an odd fish in many ways, starting with the theme, of course.
The basic premise is that all those tinfoil-wearing conspiracy theorists are right and there really are unseen powerful secret groups manipulating world events.
In the game this manifests itself with players constructing decks made up of two basic kinds of cards: Groups, which the player is trying to control or destroy, and Plots, which are the tools used to help get control, destroy or defend groups.
The game is heavily satirical and explicitly not Politically Correct, although all groups, ideologies and cultures are mocked equally.
Also making the game an odd duck is its status. Is it dead, alive or something in between?
On the one hand, it's a member of the Class of 1995 first wave of CCG's that came out after Magic: The Gathering was recognized as having created a whole new genre of games. Only a handful of games from that era survive, although M:TG is going strong.
On the other hand, INWO is still available from Steve Jackson Games, the original publisher, which would seem to qualify it as "alive."
But on yet another hand, there hasn't been anything new published for about a decade, which implies a certain like of vitality, to say the least.
However you characterize it, the current state of INWO means that it avoids some of the more annoying aspects of CCGs. No cards have become obsolete. There is a finite set to collect and yet there's always the possibility some new cards will show up.
The M:TG-style collectibility is further undermined by Steve Jackson's less than wholehearted support of the concept. Yes, he admittedly jumped on the bandwagon, by his own account, but never went whole hog. There were very few promo cards and no ultra rares. There are at least two ways to buy into the game while by-passing the whole collectible aspect. SJG offers a "One-with-everything factory set" that includes all the first edition cards. There is also the INWO Subgenius (which is even more weird than INWO) which is a completely standalone 100-card INWO game but also fully compatible with the regular INWO.
Players build a conspiracy structure based on their particular variety of Illuminati (UFOs, Bemuda Triangle, Bavarian Illuminati, etc.) trying to meet their goal. This can involve controlling a certain number of groups, but can also involve destroying groups or meeting other special victory conditions. The available groups run the gamut from personalities such as Bill Clinton, countries such as Canada, organizations such as the CIA or even loose groups of like-minded folks like wargamers!.
As a multi-player game INWO is best played with a group, but the off-beat theme may make it hard to find a group that are all interested in playing it. I think a wargaming group may be willing to try it, it is after all, a game of conquest, but is is not really a game of maneuver. There's a lot of strategy in it but it tends to be more Sun Tzu or Machiavelli than Clausewitz or Napoleon.
The game is, as I noted, still available from Steve Jackson Games, but players can also pick up cards off of eBay on a regular basis. Casual players who want to try the game out can either buy the Subgenius expansion or the regular Illuminati non-collectible card game, which plays much the same.