Olive said:Ok, what else is worth getting in the book? I like the current D20M classes a lot myself, but how about the gear etc? Could that be ported over?
A discussion on d20 Modern classes in T20 can be found at this link (to the Citizens of the Imperium board). I see no reason why you couldn't use them in T20.
Gear can be a problem, particularly with weapons since the combat systems have some differences and T20 weapons would be extremely lethal in d20 Modern (a FGMP-15 does 9d20 damage with a crit on an 18 or higher). There are conversion rules for armor in the main book to bring it back and forth. Everything else can move freely between systems.
T20 is pretty much "one stop shopping" if you want to start a d20 science fiction game. Granted, most of the stuff is realistic and based on science so you won't find people getting mutations from exposure to radiation or other science fantasy stuff - but just about everything else is there. You get complete world generation rules, prior history rules, vehicle combat & construction rules, creature creation & ecosystem rules, and the starship combat & construction rules.