The Web Spell says the creatures afected “can’t move”. So, I have some question about it. Is you are afected:
Can you attack?
Can you cast spells?
Can you use a Shield (gaining the bonus to your AC)?
Have your enemies any Attack bonus (like when you are fallen on the ground)?
We have always played it as “can’t attack, can’t cast spells without Quiet Magic (‘minimal words and gestures’), no shield / Dex to AC, backstab eligible”
I usually required a spear or polearm to attack characters entangled in a web (unless it’s a spider making the attack itself or creature with “free action”) since it’s a full 10x10 area and I imagine the webs filling the whole thing.