What was too much? The departure from "normal" 3e/3.5e/PF d20 is what we're striving to get, but yet - we want to stay within a system that's familiar to us. So it's a double edged sword of sorts - we want the d20 engine, we don't want to clunkiness that comes with it. (Understanding, of course, that 'clunkiness' is a subjective opinion.)
It's hard to quantify. I've really liked a few d20 games that added new rules to allow gaming in other genres. Of those, Omega World really stands out as genius for me. OW is only about 40 pages, but it takes d20 into post-apocalyptic with the really old-school feel of Gamma World. It makes changes that are easy to grasp and that make sense for the feel of the game. We didn't have to throw out what we already knew about the system. We just added new stuff to it. Star Wars (revised was better for me) and Judge Dredd were similar. You get a lot of return in good game play for a little investment of adding to the d20 system you already know.
It boils down to the idea that a little change goes a long way. Conan presented too much change for fantasy gaming for our group. Really, d20 D&D does fantasy gaming very well. Conan would have done better for us had the game decided what few changes were really necessary to bring out the flavor of the genre and go with those. Making
everything new & different was just too much for us.
If I were to run a Hyborian game, I would be more prone to do it with the basic d20 engine with a few changes to make it more like the novels. It's really more about capturing the feel of the genre than trying to let the rules do it. I would probably just restrict spellcasting to NPCs, so the players are the barbarians, fighters and rogues about which Howard mainly wrote. Then, I'm free to run the spellcasters as the dastardly villians from the stories without over-worrying the application of all the d20 magic rules. The magic of d20 really doesn't fit the feel of the setting overall, but it easy to throw out the NPC's fireballs but leave in the odd illusion or charm. Taking magic largely out of the game really frees up the engine. The racial modifiers and some of the feats from the Conan book might be handy, and the setting information is definitely useful. Another great aid is a map from one of the older novels that has Hyboria drawn over an outline of the modern world which helps put everything in persepctive. For instance, telling someone that Cimmeria is like Scandinavia instantly gives them perspective.
More likely and to echo the recommendation above, I would do Conan with
Savage Worlds if I could get my group to go for it. It is a much simpler system and lends itself to heroic play that doesn't get mired in detail. There is a free test drive at the web site linked above, and there is a Savage Hyboria conversion here:
Savage Worlds™ List | Conversions
Good luck and have fun with however you play it.
