I’d had a notion that both Buck Rogers XXVc (1990) and Gamma World 4th edition (1992) roleplaying games were sci-fi adaptations of the AD&D 2e fantasy rules. Having both in the shop at the moment, I began studying them to see how each modified the classic rules to fit a science fiction setting. Surprises awaited!
XXVc (1990) – the game nobody asked for – was a pet project driven by Lorraine Williams at TSR, who had a family connection to Buck Rogers licensing.
Turns out, it’s an excellent game set in a retro-futuristic Solar System. No relation at all to the TV series, but instead rooted in the original Buck Rogers pulps.
So not at all the light-hearted campy sci-fi most of us all know from the TV show. Instead XXVc has an intense, visceral, and disturbing setting more in line with GURPS Transhuman Space (2000s) RPG.
XXVc released the year after Advanced Dungeons & Dragons 2nd Edition, and deviates only a little from the AD&D2e rules. We’ll dig into that shortly.
Gamma World 4th Edition (1992) falls right in the middle of a long line of iterations following the legendary 1978 first edition.
GW4 also returned the rules back to a kinda-sorta-compatibility to the contemporary AD&D rules that GW1 followed. Except this time AD&D 2e was the current ruleset.
And its 1992 release, 2 years after XXVc, meant that GW4 had some benefit from the experimentation AD&D 2e underwent with the Brown “Complete” Guides.
I played GW4 many years ago, with little exposure since then. Reading through the book now, I was left a bit stunned.
Ascending Armor Class?! A Base Attack Bonus (BAB) style hit calculation?!
These are core components of the D&D 3rd edition (2000) “D20” rules system. But GW4 retains AD&D elements as well.
Holy Cow.
GW4 (1992) is a missing link between AD&D and the D20 rules.
Being unrelated scifi games using the AD&D 2e framework gave the designers the freedom to experiment, showing us alternate paths the 2e rules can take… paths that were indeed taken by later games.
Let’s take a look at each, with some contents shots, followed by comparisons of each to AD&D2e and D&D3e.
Buck Rogers XXVc
Buck Rogers XXVc (The 25th Century) [BOX SET]
1990 … Mike Pondsmith & Kim Mohan & Flint Dille & Jon Pickens & Scott Haring & James M. Ward & Jerry Bingham (covers) & Rob Caswell (interior art) … TSR 3562 … ISBN 0880388471
Alas, XXVc is long out-of-print, with no legal PDF available. However, there is a retroclone available at DTRPG: Overlords of Dimension-25 (PDF / Print)
The full XXVc game line detailed at my RPG Reference Site
Reference pics
XXVc / AD&D 2e Comparison shots
Stats: Here you can see with STR & DEX that XXVc follows the AD&D2e system closely. There is a further stat, called TECH.
Classes in XXVc are Rocketjock, Warrior, Scout, Engineer, Rogue, and Medic. They parallel their counterparts’ experience point progression in AD&D.
Saving Throws in XXVc depart from AD&D by being based on race instead of class. Races are planet-based (Terrans, Martians, Lunarians, Venusians, and Mercurians) or “Gennies” (Genetically-modified races: Tinkers, Workers, Terrines, Delphs, Lowlanders, Desert Runners, Stormriders, and Spacers).
THACO is retained in XXVc, virtually unchanged.
AD&D’s Nonweapon Proficiencies evolved into a discrete skill system in XXVc.
Gamma World, 4th edition
Gamma World, 4th edition
1992 … Bruce Nesmith & James M. Ward … 192 pages + fold-out map … TSR 7514 … ISBN 1560764015
Noble Knight | Amazon | DriveThruRPG (PDF / Reprint)
Gamma World 4e product line detailed at my RPG Reference Site
Reference pics
GW4 & AD&D2e/D&D3e Comparison shots
Gamma World 4e Stats are STR (split into Mental Strength & Physical Strength), DX, CN, IN, CH, plus Senses (SN) and Mutation Power (MP).
GW4’s Genotypes – aka Races – will be familiar to players of other GW editions: Pure Strain Humans, Altered Humans, Mutated Animals, Sentient Plants.
Classes (Enforcer, Esper, Examiner, Scout) are new to GW4e. Each shares an XP progression similar to an AD&D Fighter.
Here is the GW4e Level progression compared with D&D3e, which had scaled back the escalation in the higher levels quite a bit. Not a match.
GW4 uses Ascending Armor Class, a big deviation from AD&D2e.
THAC0 from AD&D morphs into GW4’s THAC, which acts the same as D20’s Base Attack Bonus (BAB). PC’s also have a Mental Defense (MD) score, which acts as AC vs Mental Attacks.
GW4 (1992) uses the same Attack Roll function as D&D 3e (2000)!
GW4 Armor provides the same AC bonuses that D&D3e would use 8 years later.
To my knowledge, Gamma World 4th edition is the first to use the combat mechanic later popularized in the D20 system.
Nevertheless, GW4 still uses “roll under” for ability and skill checks, like AD&D. The DM determines a Difficulty (0, 5, 10, 15), which is added to the player’s roll. If that result is under the ability or skill, then the player succeeds. (The D20 system uses a “roll high” method in line with the combat system. A “DC” is assigned, and the D20 roll + skill modifiers must beat that DC.)
In summary, I view GW4 as a transitional evolutionary link between AD&D 2nd Edition and D&D 3rd edition.
See Also:
I think Gamma World 4th is the most solid entry in the whole series: complete rules and plenty of setting lore. I agree, it does indeed feel like a bridge between 2e AD&D and the d20 engine to come. My only quibble about 4th is that it uses a class system for player characters and I prefer Gamma World to be classless, but some might actually find that to be a plus!
Buck Rogers I only played in the form of the old Gold Box PC games. It very much played like AD&D reflavored for space, down to grenades in place of fireballs. I was much more impressed by the world building, with everything set in our Solar System but fully terraformed and all the “aliens” being genetically modified people & animals.
Great write ups!
Thank ye kindly!