Limbo has gone through a startling number of changes for a plane of total chaos. In first edition, really intelligent characters could stabilize miles of material, but no one could control what exists in such regions. In third edition, the area was very reduced and some rare people could use the matter in flux to create whatever they want. Most were stuck with just converting one element to another. In fifth edition, the area is still pretty small, but now most people can mentally force their surroundings into desired forms.

Personally, I am more a fan of the first edition’s style than the others. Characters should be able to keep themselves and their gear on them stable, but not actually make anything from their surroundings. And the reason why is simple- Limbo contains everything a human can imagine. The Far Realm is where the laws of physics are completely different, something that does not apply to Limbo.

How I envision the plane is an infinite junkyard filled with everything and anything. That includes creatures as well as objects. Trying to come up with a standard encounter chart for Limbo isn’t going to work, so I came up with something that works for me. What they boil down to is genre and era. Fantasy makes up the lion’s share of the percentile, but all the other genres also are found on it, from romance to horror. For eras, I use historical ages- Stone Age, Bronze Age, Information Age, etc. and threw in a few for the future as well. Combined they cover everything that I would be concerned with the party discovering on the plane. I read the results of both rolls and then come up with some objects or a location that fits. To make it weirder, I roll a few times on each and combine the results.

Objects that are stabilized can be taken away from Limbo, but will always leak a little chaos, causing objects and creatures around them to warp in minor ways.

As for creatures, I use the generic monster stats in Silent Legions (it wouldn’t be difficult to come up with your own) and then 1d6 mutations from Mutant Future or the Metamorphica.

Yes, that does means one could find a nuclear power plant in Limbo. The problems are understanding it, stabilizing it, surviving it (in case anyone looks into the core) and then transporting it if the characters want to save the plant for some reason. Of course the power plant may run on nuclear material that is fantastic, possibly nuclear dragon scales or blood, illithid brains bathed in quicksilver or whatever else comes off the top of my head.

Limbo is the place to find great wealth and great horror, probably both. For those who survive its depths, they should never be the same.