Not an obscure rule, but something very strange. Encumbrance! I just finished making a new 2e character, and when writing down her Encumbrance categories, I was suddenly struck by how weird they are.
So with 18/56 (woot!) Strength, she can lift 305 pounds. She is unencumbered until she exceeds 160 pounds. Then it gets weird.
At 161-200 pounds...no allowance for fractional weights, which there are several items that weight 1/2 or 1/10 of a pound, which leads me to wonder what you're intended to do if you're at 160.2 pounds, lol, her speed drops from 12" (lol) to 8".
Ok, that's a 39 pound range. Then we go to 200-238 where she's down to 6". Then 239-277 for 4", and finally 270-305 where she's down to 1"- which means she wouldn't even be able to move 5' at combat speed, if that ever were to happen, as I understand the rules for combat speed.
Ok so, the weirdness. She can carry over half her maximum press without any problems, and then suddenly there's these comparatively small 35-38 pound increments where she starts being increasingly more burdened.
I don't know, it just seems strange to be like "yeah, 160 pounds no problem...oh wait, you went from 199-200?! Half speed for you!"
I'm curious if anyone knows the rationale here- as I understand it, a normal human starts being slowed down when they carry more than 20% of their own bodyweight, and here I have a character who can carry around over 150% of their own bodyweight and not care, and then suddenly another 40 pounds and they're staggering around at half sleep, lol.