Oh, of course there's more to do in GURPS than you'll find in the corebook - entire bookshelves worth of settings and options and variants and so on, your (Bob's) own IST being a notable example - but without the core rules, there's not a whole lot of point in getting the rest...
As for Slayers and D&D, I'll note that a bit of research discovers that in the GoO D20 Slayers book, Lina is listed as Lv19 at the end of the first series ranging up to Lv23 at the end of Try - but they use completely new classes for everything but Rogue, and even that is heavily modified enough to get a complete listing. Apparently, the only thing you'll actually use from the basic Player's Hand Book is that one table that's not included in the SRD saying how much experience it takes to gain a level, and when you get new Feats and Stat bumps.
d20 still rubs me the wrong way, even so, though less so in the Slayers version. I do not like it, Sam I Am. (Not even after trying it.)
- CD
--
"Anko, what you do in your free time is your own choice. Use it wisely. And if you do not use it wisely, make sure you thoroughly enjoy whatever unwise thing you are doing." - HymnOfRagnorok as Orochimaru at SpaceBattles
woot Med. Eng., verb, 1st & 3rd pers. prsnt. sg. know, knows
As for Slayers and D&D, I'll note that a bit of research discovers that in the GoO D20 Slayers book, Lina is listed as Lv19 at the end of the first series ranging up to Lv23 at the end of Try - but they use completely new classes for everything but Rogue, and even that is heavily modified enough to get a complete listing. Apparently, the only thing you'll actually use from the basic Player's Hand Book is that one table that's not included in the SRD saying how much experience it takes to gain a level, and when you get new Feats and Stat bumps.
d20 still rubs me the wrong way, even so, though less so in the Slayers version. I do not like it, Sam I Am. (Not even after trying it.)
- CD
--
"Anko, what you do in your free time is your own choice. Use it wisely. And if you do not use it wisely, make sure you thoroughly enjoy whatever unwise thing you are doing." - HymnOfRagnorok as Orochimaru at SpaceBattles
woot Med. Eng., verb, 1st & 3rd pers. prsnt. sg. know, knows