They have the house rule that nat 1s and 20s work on skill checks, too.
I actually failed an illithid wisdom check 0 one time because I rolled a 1.
Yeah, nat1 is auto-failure no matter what, that's the same as in D&D, not a house rule...generally if a task is deemed to need a roll in the first place a nat1 will fail it. A difficulty of 0 generally means it's super easy but will still require a dice roll if the DM still wants you to have a chance to fail it as it might be a minimal challenge but still a challenge. But I don't know about nat20s...if that is consistent with D&D then in the event that difficulties higher than 20 exist in the game(which we don't know if they do), a nat20 may not succeed...depending on what bonuses you have.
