Running established D&D settings with systems other than D&D?

[Isamu Dyson]

I have in mind Greyhawk/The Forgotten Realms/Dragonlance/Dark Sun/Ravenloft/Eberron/etc.

Have you ever done this? If so, how did it turn out?

[Eldan]

I've run Planescape in both Fate and Mutants and Masterminds. Works quite well. The first for the philosophy, the second for really weird party members. Because if there is a system that can model a flying skull scholar who summons avalanches of skulls in a lot of detail, it's M&M.

[Rhynn]

I'll assume retroclones count as D&D...

Unisystem works pretty much perfectly. It'd be my system of choice for running Ravenloft (a far better fit than any of the official Ravenloft material, 2E or 3E). The Dungeons & Zombies sourcebook does much of the work for you. Also, if you google "unisystem midnight conversion" the first result should be a download for a PDF of Colin Chapman's conversion of Midnight for Unisystem.

[erikun]

I'd assume it depends a lot on what you are trying to model in the new system. For something like Planescape or Spelljammer, where the big deal are the NPCs and groups and travelling places, you could probably swap the system and keep the interesting bits. For something like Forgotten Realms or Dragonlance, I'd be concerned that there are more assumptions about typical D&D mechanics in the setting itself, and it would require making sure they work with the new system.

I've been looking at taking a Pathfinder adventure and running it on the HeroQuest system (or possibly Fate, if nobody wants HQ) but haven't had the time to put it together. My biggest concern is that the adventure assumes that players will just move from combat to combat, killing everything in each, while that might not be a reasonable assumption outside the D&D system.

[NichG]

I've run Planescape using a modified set of the 7th Sea rules, which worked pretty well. Just don't try to have a game about 5 PCs versus one Elder Evil or something - the system isn't great for solitary enemies who are the equal of multiple PCs.

You also have to play with status effects and consequences to keep fights interesting - 7th Sea can degenerate into a battle of attrition - a dramatic-wound-slugfest - if you let it. But if you make sure that enemies have interesting effects (should be easy in Planescape) then it can help keep up the tension (for example, my players fought something that could generate prismatic ray-like effects on the Plane of Radiance; even though many of the results would just cause some fleshwounds or a dramatic if they hit, they were afraid enough of the 1 in 7 chance of 'go to another plane' that the fight had some tension even though none of them got tagged with that).

[InQbait]

I don't bother with established settings because it is too much reading and/or too much to remember, and I feel straitjacketed. It's a lot of, "oh, you can't do this because..." or, "Aren't you forgetting about this important piece of history or this important NPC who can do anything?" It's really annoying and so that's why I prefer to create my own settings to play in. It's not exactly easy, but it pays off

I usually create my own systems of rules to go with the setting, but sometimes I get lazy and just use Pathfinder

[skyth]

Well, I've done the opposite once. I've sent my D&D party to Kulthea for a quest.

[Yora]

I've play Planescape, Dark Sun, and Forgotten Realms with the AD&D boxes, but using Pathfinder books for characters and creatures. When playing FR and DS, I also play without alignment. (You kind of have to have it in Planescape, but even then only outsiders have alignment and humanoids are always Neutral.)

And when I play Sci-Fi gams like Mass Effect or Ghost in the Shell, I always use Star Wars Saga Edition.

[NichG]

Planescape works better without 'strong' alignment rules for PCs/humans anyhow; helps put more focus on the factions/weirdness of the planes rather than the big cosmic Evil vs Evil/Good vs Evil conflicts (which you can really get in any setting). Planescape is a lot more interesting when you ask about why exceptions to the rule are happening, e.g. 'why is this devil being so friendly/helpful to that celestial?' rather than the usual kill-on-sight.

[The Dark Fiddler]

I've run Planescape in both Fate and Mutants and Masterminds.

Similarly, around when Fate Core came out I heard an exceedingly large amount of talk about running Eberron in it. Not sure how it works, because I wasn't interested.