What RPG worlds/systems work best together in crossover combinations? [closed]

Question

I'm curious: What RPG worlds have you combined most successfully in a crossover setting as a GM? (Or what was the best crossover that you played as a player?)

My best experiences almost always included Chaosium's Call of Cthulhu or White Wolf's (old) World of Darkness (and their respective systems). The longest crossover campaigns we played were:

• a CoC / oldWoD campaign, in which player vampires/werewolves investigated their own relationship to the Mythos which mostly replaced their own official origin stories. (We used the Storyteller system for this.)

• a CoC / oldWoD / SLA Industries campaign, which was loosely related to the abovementioned one, and in which the players as SLA Operatives faced the Elder Gods and their oldWoD-based minions in their company-assigned quest to conquer "Earth". (We used a homebrew mix of SLA/CoC rules for this.)

What combinations would you recommend, what crossover is worth giving a try?

Answer 1

I've played in a few PbEM's that were basically the old World of Darkness with a major Lovecraftian theme and they seem to be both popular and succesful. There was also some stuff put out by pinacle to bring oWoD werewolves into the Weird West (of Deadlands) that a GM friend of mine used somewhat sparingly to good effect.

... me personally, I have run a Firefly/Serenity game set in the wider Aliens (and Predator) movie universe. It worked pretty well as the majority of the themes and tropes are already in place (mega-corporations are the same as oppresive governments after all). Early sessions were just treating the firefly planets and political set-up as a small system on the edge of Colonial space and then we later moved up the scope so the players were interacting with a larger galaxy and some of the traditional 'company as bad guy' plots.

Answer 2

I'm going to recommend GURPS, the Generic, Universal RolePlaying System, in case you've never run across it. GURPS is designed to handle any setting you can throw at it. The default setting for the current edition of GURPS is the Infinite Worlds settings found originally in GURPS Time Travel

The shortest distance between any two settings is GURPS.

That said, pretty much any setting-agnostic system should be good for doing crossovers. We used the PDQ system to handle our revisit to the Scion setting when we got so sick of Scion's native system that we just couldn't stand it any more.

You might like Savage Worlds, too.

A large part of this decision will come down to which system you like, how much weight you want, and how much work you need done for you. GURPS is heaviest of these that I recommend, yet it has the most support and the most work done for you, in terms of there being rules / stats for anything you can think of probably already available.

Answer 3

There are several generic systems with multiple genre sourcebooks.

EABA has some fantasy, sci-fi, and post-apocalyptic setting books, and a system that can run from street-level supers down to kids in the hood... and mid-magic high fantasy as well as paranormal-free.

CORPS, by the same author/company as EABA, has fantasy, horror, and post-apocalyptic settings, as well... and was originally a moderns conspiracy game. It runs no paranormal to street level supers or low mana magic, fairly easily. It handles power levels in the same ranges as EABA.

Hero System can handle nobodies (-25 point incompetent normals) to demigods (5000 point greek demigods), and has genre books for SF, Fantasy, comic book supers on both street level and 4 color, as well as comic book magic-based supers, Chanbara and Realistic Martial Arts, moderns, Cyberpunk, horror and westerns. (Sups from 4E to 5E are perfectly useable with either edition; 6E has some differences.)

GURPS has more Genre books than any other game I know of. Many complain that it doesn't do genres as well as other games mechanically, adapting the setting to the engine, rather than the engine to the setting.

TORG is a genre-mashing game... Earth invaded by alternate realities. PC's from any one... and not of need the same ones. tech-free magic heavy to Cyberpunk, at least three kinds of horror, several action-adventure oriented cosms, 2 different cyberpunk realities... It's pretty wild. Currently not in print, may still be available electronically and some FLGSs have it still.

d6 system is likewise multiple systems with the same core rules distributed, and a variety of genres. Counting stuff that's hard to find: Superheroes, fantasy, Star Wars, MIB, Indianna Jones, non-SW space opera, horror ... easily cross integrated. Now open-licensed, too... hard to find in dead tree.

All of the above can readily genre-mash. I've mixed streetlevel supers with fantasy in Hero System; Fantasy with Illuminati University in GURPS; Humor and Fantasy in CORPS. EABA's settings include a few with some genre-mashing already. Torg is a blast... but if one doesn't like genre mashing, it is going to be unhappiness generation...

A few others I've not used, but know people who have.

Paladium Books' games Since they all use pretty much the same system, they can be used readily for mash-ups. System of questionable merit to many; fans tend to be quite vocally in favor of it.

Chaosium's BRP and derivatives... The various games all scale the same, so characters from one can be used in another easily. various rules in older editions don't match up, but can easily be ported. One bloke I know of used CoC's sanity rules in his ElfQuest game. Another used EQ for the elves in his non-EQ RuneQuest III game.

D20 3.0 SRD derivatives. Too many individual things to list; most stick close to core d20, and can be mixed and matched with only minor issues. Everything from Dune-meets-Warhammer-Feel (Fading Suns D20) to biblical fantasy, and most points between.

All of these have a variety of strengths and weaknesses; some do certain genres really well and others poorly (EG: GURPS Supers in mashups tended to have issues with mages being WAY more powerful at the 300-500 point range than supers...) that are too much to handle in this already long answer.

Answer 4

I'm having huge success with a crossover of Greyhawk and Earthdawn. I'm using the Earthdawn 3rd edition rules/setting and importing huge chunks of chewy gygaxian dungeon/hex-crawling. Extremely fun so far.

[A comment on the previous Earthdawn/Shadowrun conversation...

Earthdawn is recognized by the FASA designers as Shadowrun's mythic past (the peak and fall of the previous mana cycle).

"Atlantean" tech are references to the isle of Thera (modern day Santorini). There are characters who live through (some of) both settings, like Queen Alachia, and the Dragon Dunzelkahn/Mountainshadow.]

Answer 5

D20 Modern Urban Arcana and D&D 3.5 are explicitly written to allow for crossovers. The crossover is more commonly from D&D to D20 Modern than vice versa, but there are notes for doing it both ways.

Unfortunately both are out of print, but should be reasonably available.

Answer 6

Shadowrun and Earthdawn. Although SR and ED are not mechanically compatible to each other the share the same metaplot of their background, although separated by over six thousand years.

There is also at least one (older) official published adventure involving SR and ED in a cross-over campaign (Harlequin's Back (spoiler!)).

Answer 7

Any percentile system (BRP, Chameleon Eclectic, OpenQuest, FASA Star Trek etc) is fairly cross compatible, even with d20 roll under systems (AD&D, and in particular the complete Psionics Handbook. Because of the nature of percentile systems, converting characters is far more straight forward than any other type of system, which lends itself incredibly well to genre mashups.

Most ORE systems are fairly compatible, again due to the nature of the mechanic and how it tops out at 10d10 for the pool. Nemesis, Reign and Wild Talents are all fairly compatible with each other, and Monsters & Other Childish Things as well to a lesser degree (A Dirty World sits on the side entirely).

Dice pool systems like Shadowrun and World of Darkness are very compatible as well, the odds of 5 or 6 on d6 are roughly the same as 8, 9 or 0 on d10, so again any dice ratings can be easily converted one way or the other.

FATE based systems, particularly thanks to how Aspects work are also quite cross compatible, and Starblazer Adventures and Legends of Anglerre are even explicitly designed to support unusual genre crossovers.

Interestingly, the SAGA system used in Dragonlance 5th Age and Marvel Super Heroes is with only slight modifications compatible with the D6 system used in Star Wars. This is noteworthy because SAGA uses cards and Star Wars uses dice.

Not surprisingly, Aces & Eights and HackMaster Basic work fairly well together, given the latter was derived from the former.

A lot of games from when AD&D was at its most popular were pretty much clones, while changing the theme. Palladium Fantasy RPG was so close that I read a Palladium supplement without having read the core rules and understood every little bit. The BECMI and AD&D lines were also very close to being compatible, and there are a lot of other games which fit in quite easily, including BRP.

As for worlds, there are countless mashups that can work. The entire Urban Fantasy genre is a mashup in itself. Starblazer Adventures (the comics) as well as some supplements in Star Wars showed a solid combination between fantasy and sci-fi (the French comic series Ythaq also does this), and something like Sliders taken to the next step would do this as well. There have been X-Men and Star Trek crossovers, which worked quite well (in narrative). The Transhuman Space setting also begs to be mixed with something else, because by itself it's pretty tough to see what you would do, one idea I was particularly fond of was mixing it in with JAGS Wonderland.

Answer 8

I have run several crossovers (as I now understand the question!) that were not designed to be used together.

Most recently, I used the Company rules from Reign to supplement the disappointing (in my view) realm management rules from the latest A Song of Ice and Fire game. I think it worked reasonably well - my players did not like the change mid-game - but the ASoIaF rules were (again, in my opinion) a poor and nonsensical add-on to the game, whereas the Company rules in Reign are designed to generically handle groups - from a small group like a gang, through a guild, through an empire. I was able to use the realm management rules to do what I wanted - which was to both drive and reflect PC action. If I were to run another ASoIaF game, I would use the Reign rules from the outset.

Previously, I mashed-up The Riddle of Steel and Ars Magica to produce a homebrewed Riddle of Magic. The game was basically AM's skills and magic with TRoS's combat. It was a short game, but, I think it would be worth pursuing the fusion experiment further.

PS - I hope the RPGGeek links are OK - I like the way it collects systems and products.

Answer 9

Labyrinth Lord and Mutant Future, being based on the same ruleset, are suitable for doing crossovers. (Just as early D&D editions and Gamma World—of which LL and MF are more-or-less clones—were suited to crossing over.) Possibly involving time-travel, or perhaps an adventure à la "Expedition to the Barrier Peaks" where you have Mutant Future squamous things somehow transported to your medieval D&D setting.

Although, if your LL game is gonzo enough, that wouldn't necessarily count as a crossover.

Answer 10

Old World of Darkness (and possibly new as well) and In Nomine work so well together at times that it's painful. (And so poorly at others that it's even moreso. The mechanics conversion is a fright, but the settings mashup in a variety of interesting ways.