Going off my last post a bit, though less about the differences between editions and more about the ongoing move towards more rigid boundaries and a precise regimen of player-controlled abilities, the player-centric design. You can see that this was something the 4e design team noted earlier on and attempted to rectify in the design of another game line: the post-apocalyptic Gamma World.
While the seventh edition of the venerable Gamma World—the one using 4th Edition D&D rules and branding, so I’ll refer to it as Gamma World 4e because I’m lazy—used a lot of 4e’s core rules, it gave them new and interesting twists. The way it handles ammo is beautiful: it assumes you’re saving your bullets for important threats, so instead of tracking individual rifle rounds, you’re allowed to make one free guns attack per combat—“conserving” ammo. If you make more than one, you’d better go to town shooting, because if you used more than one bullet you run out of ammo immediately at the end of combat. Gamey, but it creates a nice risk:reward balance in preserving your supplies without tracking pointless minutiae.
Character mutations came in card form, in two varieties: you get a constant stream of Alpha Mutations, your mutations replacing each other constantly—the corrupted world’s ongoing changes to your genetic structure whenever you wander into a different part of the nuclear, chemical, and/or biological wasteland—and Omega Tech, the bizarre far-future technology of the Lost Ancients, which could run out of power and have to be scrapped. Again, gamey, but I like the idea.
Then we get into the more abstract implementations. Your starting “mutations” are up to player definition. The book’s example is rolling “rat swarm” and “feline:” the book prompts the player to come up with some way to rectify these into a character concept, such as a hive-mind of rats that takes a leonine shape, or a swarm of kittens. Similarly, the gear was all abstract: Light Armor might be a heavy trenchcoat, football padding, or a bunch of mattresses tied to your chest; your Big Club might be a baseball bat, a lead pipe, or a telephone pole.
See what I mean about the design team recognizing the backlash over 4e’s rigidity, and how they attempted to compensate? The abstract elements mean that the game is still player-centric, but it rewards (and expects) more creative input from players in how things look and act. The character cards meant that instead of focusing on your character build—planning five levels ahead for which feats you got, which Paragon Path to take—the focus was on the here-and-now, on the powers you get and how you use them. Since your new “powers” and paths were all random and “leveling” gave flat bonuses (+1 to hit, +5 HP), there was no character optimization to plan. Yet you still get plenty of diversity and options in one character—from new mutation/tech cards every 20 minutes or whatever.
I feel bad for Gamma World 4e. First, consumers bagged on its mutation-changing mechanics, calling it a CCG-style cash grab, since the way to more mutation/tech options was through buying booster packs of ~15 cards. Then, the product line turned out to be one box set, two expansions, and a single ~120 card set, and people complained because there wasn’t enough to the game. Only taking characters to 10th level reinforced that “it’s the red-headed stepchild” view. It had a lot of interesting mechanical concepts retained from 4e, yet had a more flexible and openly creative vibe to it.
I’d love to run it in either one-off or side-game capacity, but that might be pushing my luck: it tends to go full gonzo, even if you’re trying to keep a respectful distance from wacky hijinks to give post-apocalyptic its gritty due. Even as a side-game, the lunacy of the setting has always been almost overpowering… excepting the sixth (d20) and fifth (Alternity) editions, which were Fallout-lite and sucked respectively.