New Eleusis is one of my favorite card games.
Many other games rely on logical deduction. This game emphasizes induction: coming up with an explanation that fits the observed facts. New Eleusis doesn't require any scientific background, but it does require a willingness to think. This is not a game for the intellectually lazy.
Here are two html pages about New Eleusis, one giving the rules of the game and the other giving an introduction and some hints. In addition, there is a two page, 700K postscript version (Sorry: deleted for lack of disk space) which is virtually identical to the html version, but can be printed on a double-sided 8.5" by 11" sheet of paper; this is convenient if you want to make lots of copies to hand out to people.
In addition, here is an email message from Marc Drexler describing some advanced rules. (Marc is a superb New Eleusis player who has done much to advance interest in the game here on the East Coast.) When I have time I'll try to properly integrate this material (or at least turn it into decent HTML!).
Dave Moser has created a registry page to help people locate others who might like to play.
I claim no credit for the game itself, but I wrote these summaries, and they are copyrighted. Permission is hereby granted for anyone to make any number of unmodified copies for personal (non-commercial) use only.
May 31, 1995
Revised January 20, 1997
Revised again March 6, 1998
Note: my email address on the postscript version is out of date; it should be firstname.lastname@example.org