Grimrock

The Vault has the puzzle with lightning bolts and spider.. I think it is not supposed to be this easy.
I don't see why this would be intentional, regardless there is an easy way to avoid this... make it so that if the spider stands still then the lightning bolts keep coming at steady intervals, thus not allowing player to stand where he is in this setup (since the pressure plate the spider gets stuck on would trigger lightning bolt on the column you are standing, however, since it only happens once on each press, you can either dodge it and quickly get back into position or just eat it).

I don't know if this is doable 100% of the time.. but i did it twice in a row.

Edit: ok, does not happen always, however by the off chance that the spider manages to recover from above setup you can keep quickly moving left and right and the spider is as helpless as ever since it will at most move between the two adjacent pressure plates.

Pretty sure it's a side effect of the AI. The mobs try and seek the shortest path to you normally (so going around pits) but will continue towards you if necessary regardless of things in the way like gates or, in this case, pits. It seems to cycle through options every x seconds so they will occasionally wander off but will generally go back to hugging pits, gates again shortly after.

Well considering that this particular spider is bit special (being integral to the challenge factor of this bit) I would say they should have given him some special attention considering his situation .