Has anyone played either of these two? I'm kinda curious about them, and I've been on a big rules-light kick lately.
Sell me on 'em. Scare me away. Tell me what does what they do better, but with cake.
Rules-light is rules-good! A big rulebook is a big pain. Fortunately, you're looking at some good stuff, especially re: Gamma World. But I can tell you about them both.
If you go Gamma World, definitely go 1st Edition. Subsequent editions just added more junk IMO, and made the mistake of trying to fill in the world and give you a setting. 1st Edition Gamma World gives you game mechanics, a blank hex map of the USA (with coast lines adjusted for post-apocalyptic conditions... sorry Florida!) and tells you to go crazy with it. So your Gamma World can be anything you want: from the bland and vaguely humorous world of misspelled 20th century names where people use stop signs for shields (the direction the official products went) to a dark and mostly alien world dominated by giant critters that look like they came from the Burgess Shale while humans eke out survival as spear-chucking primitives.
The rules are nice and minimal. You have your stats, you have mutations if you're a mutant (some good, some bad) and starting gear suitable for a post-apocalyptic neo-caveman. All of this is rolled randomly, which means that if you're a mutant you can come up with all kinds of interesting combinations of powers/defects. You can even play a sapient plant (obviously mutated) if that suits your fancy. A psionic Ficus with a ray gun and a spear, perhaps.
Besides that you have rules for combat (quite straightforward, and familiar to you from old school D&D) and some rules for figuring out high tech ("ancient") artifacts. Beyond that you've got some monsters and a few other things and then you're on your own. There is part of a sample adventure. One thing that is interesting is the advancement system: it's not really level based. Every time you accumulate so many XPs you get to roll on the advancement table, which may result in a bonus to hit in combat or some other beneficial increase. So to make an experienced character you need do no more than roll a few times on that table.
Starting characters have a lot of hit points: you roll Xd6 where X is your Constitution score. But they don't tend to increase over your career, so what you've got is what you've got. I assume all the hit points come as a result of being super-evolved... your forefathers did survive the apocalypse and the ensuing epoch of laser-beaming megafauna, after all.
Anyway, it's good, clean post-apoc fun and quite rules-light. They really just fade into the background, as they're supposed to. 1st Edition is the OD&D of Gamma World.
Star Frontiers is a different beast. It is approaching rules-medium (on a scale that calls 3.X rules-heavy or extra heavy) and it comes from a later generation of games than Gamma World. It comes with a pre-developed setting and includes a skill system (though the skills are basically focused on defining your professional accomplishments... it's not like GURPS or D20 where you have skills for looking around or climbing a tree or scratching your nose or whatever). It is still basically guided by some of the old school sensibilites, but succumbs to the trend of having lots of rules a fair amount of setting detail that some might find extraneous.
There's nothing wrong with Star Frontiers, though the mechanics might not appeal to everyone (there are no criticals and you probably won't drop someone in a single shot, even from a rifle... something that some folks want from a modern/futuristic game). It's a little more rulesy than I like, but not too much. It's better if you like the background, not as good if you don't. If you're into space combat there's a full hexmap wargame that goes with it, and despite a few warts it's not a bad game.
The other advantage to Star Frontiers is that it's free.
starfrontiers.com
WOTC is, as far as I know, evidently cool with that site. Which is pretty darn cool in my book.
