Can you spell L-A-W-S-U-I-T?
(And no, the fact that Larian is the bigger studio and would probably win is not a counterargument)
Why would there be a lawsuit? Both companies use a 3rd party licence of the same game system. Larian just got more of the lore and published subclasses etc.
There is literally no ground for any of them both to sue over 5e rules.
