Kumo desu ga nani ka.. Spidergirl in a dungeon. I need stats.

[Niro]

Well long story short, I will be running a game based on the lightnovel/manga/soon-to-be anime named "Kumo desu ga nanin ka but I have a couple of problems/questions.

1) We will be running this in a mix of pathfinder and dnd 3.5. But I wanted to hear if someone have been homebrewing the races or if I will have to do that myself

2) What do I do with level ups? Since in the story that the MC gets both stat increases and new skills at each level up.. should I just say "Screw gamebalance" and let the player have fun with his OP creature that in the end will be able to oneshot a dragon if he so wanted?

Also: Have you ever tried to run an isekai game? How did it go? What to look out for etc.

[mabriss lethe]

My first thought is that D&D might not be the best system to run this on. I don't think it's going to model what you want to do very well. Mutants and Masterminds might be a better fit as a d20 system, or just bashing a system together that does what you want. That said, If you plan on sticking to 3P: I don't know too much about the source material, but pathfinder's race building rules will probably be what you want to look at to stat out the different races.

If you want some quick and classic inspiration for D&D-as-Isekai, Look no further than the D&D cartoon from the early 80s.

[Alent]

I agree that D&D is probably not a very good system for Kumoko's Tensei Nightmare. (Kumoko would probably hate it because it has D in the title twice.)

The world of Kumo desu ga is explicitly a point buy system with additional MMO style grinding mechanics. You might be able to approximate it with the Unearthed Arcana generic class rules, maybe do a fair chunk of homebrew to it for gaining skill points and bonus feats through EXP.

I haven't tried to run an isekai myself.

[Menzath]

I think the main problem would be for non human creatures that have levels, and different ranks in their evolution, changing most of(or the entire) base creature causes a huge headache in D&D.

As soon as you mentioned the series I first thought of using hero system or something similar that's far more freeform in how characters function, while still keeping game balance to a degree.

[EldritchWeaver]

I agree that D&D is probably not a very good system for Kumoko's Tensei Nightmare. (Kumoko would probably hate it because it has D in the title twice.)

The world of Kumo desu ga is explicitly a point buy system with additional MMO style grinding mechanics. You might be able to approximate it with the Unearthed Arcana generic class rules, maybe do a fair chunk of homebrew to it for gaining skill points and bonus feats through EXP.

I haven't tried to run an isekai myself.

The closest to point-buy for D&D and PF is actually to use point-buy, but this requires to switch the foundation. There are a number of attempts, but of those I've checked out I like Eclipse: The Codex Persona (https://www.drivethrurpg.com/product/51255/Eclipse-The-Codex-Persona-Shareware) the best. It does allow replication of the base game(s) without falling apart when you leave the class confines which is a hallmark of a good point-buy system.

[Mordaedil]

Really didn't expect a thread on this before the show got its anime release.

Kinda hard to know what to recommend here, I suppose you could be an awakened giant spider in D&D and follow the shows suggestions for stats and build it backwards from drider?