

Not all the Classic edition rules were in the basic set from 1997 on - many advantages and information (including rule changes) that are in 4e Basic Set ($49.95 $29.99 for PDF + $34.95 $29.99 for PDF) are in the two Compendiums which are $26.95 (S16.99 for PDF) and $13.99 ($9.95). Appendix (replaced "Caravan from Ein Arris" which was reworked into Caravan to Ein Arris in 4e).Basic Set (Third Edition) Revised on its own can be viewed as effectively 3.25 Edition. The informal name for this version (Basic Set plus Compendiums) was "GURPS 3.5 Edition" Its formal title, along with all pre 4th edition material still in print, is GURPS Classic which can be rendered as "Classic". If you have an old Third Edition, and the new Compendium, you’ll have it all." "The Compendium also include everything from this Appendix.

Anything that’s in the Compendium will not be repeated in later books, freeing up a lot more space for brand-new stuff." Plus, finally, once and for all, the Mass Combat System, and a lot of other things that GURPS players kept asking us to repeat. These books include every advantage, disadvantage and skill that we’ve ever published (expect those that are so closely tied to specific licensed worldbooks that there would be no point in it).

"We have also released GURPS Compendium I and II. Most are for character creation – advantages, disadvantages and skills that would fit into almost any genre." Since GURPS first came out, a number of really (pardon the expression) generic rules have appeared. The Basic Set (Third Edition) Revised (1996, 1998, 1999, 2002, 2004) started life out as the 9th printing of Basic Set Third Edition (1988, 1989, 1991, 1992, 1993, 1994) but the people working on it "looked at the book and said, “Wait a minute! This is 1994!”
