Random Encounters from every Environment/Plane

[AzureKaden]

So i posed an idea to my players (Who REALLY liked it), about a game that's going to be called 'The Tower', based around a concept similar to SAO, Tower of Druaga, and DanMachi, where a mysterious tower filled with monsters from all over the world as well as from all the planes has appeared in the middle of a barren wasteland.
This tower is simple enough to construct, 100+ 'Floors' (Randomly generated super dungeons in a circular shape about 1 mile in diameter with a way up to the next floor and down to the previous), but i'm struggling with the random encounter list creation as such a long list of potential monsters makes manually compiling the lists a LONG process, and the few random encounter generators I've used in the past designate specific environments in order to shorten their lists as well.

So my question is has anyone done something like this before? And if so did you use a random generator, manually compile your lists, or something else?

Any advice/help would be greatly appreciated.

[Laserlight]

Is donjon's monster list (https://donjon.bin.sh/5e/monsters/) what you're looking for? The monsters are tagged for environment but you get the whole list. There is also a random encounter generator but it appears that does require an environment.

It's not clear why you don't want an environment tag in the first place. Are you planning on having, say, winter wolves and salamanders in the same space?

[mephnick]

Keep the actual variety of enemies per floor very simple, but use effective groupings, like a good video game. Like for a "Stone" level, use Gorgons, Xorn, Dao and Gargoyles..and that's it. However, introduce them all individually and then start mixing them up. So you start fighting Gorgons surrounded by stone victims, then later you fight gargoyles, but then later you fight gorgons with gargoyles mixed in between stone victims. Introduce Dao and Xorn individually, but then have Dao creating walls of stone the Xorn can move through easily while separating the party. So choosing the few monsters of each level is a pretty easy task, but then you can focus your efforts on making them memorable. I would advise against making each floor a "super dungeon". Everyone will get bored with the same theme for much longer than a couple sessions and creating 100 even remotely memorable floors is going to be tough enough as it is. You will get burnt out if you don't pace yourself and keep things fresh. A completely random encounter table for each floor is probably not a great idea despite my love of encounter tables. This is the one kind of situation where I would probably key cool encounters to certain rooms and have a very small randomized table of pre-built "wandering" encounters ready to go. Otherwise you could have a slog on your hands.

[JackPhoenix]

http://kobold.club/fight/#/encounter-builder provides encounter builder with pretty much every published monster (including 3rd party, excluding homebrew) with multiple filter options. It also calculates appropriate encounter difficulty for the pre-selected party. I think it's the best tool currently available for this use.

[AzureKaden]

Laserlight, i was planning things like that, but mephnick is right, making each floor ts own environment should work better.

JackPhoenix, thanks for point this generator out to me, i'd never seen this one before.

Thanks for the advice guys.

[NecroDancer]

Check out the adventure Dead in Thay for inspiration, it has multiple environmental areas thay are really cool.

[AzureKaden]

Awesome, thanks NecroDancer, i'll definitely take a look at it.