Dungeon Combat help: Single Encounters take whole sessions.

[Chauncymancer]

.
If someone dont know the rules for what they are trying, they cant do it. They have the entire round to check rules, their turn is for acting not for books. It shouldn't be set in stone, but be a general rule.

In my experience the books typically come out when Person A announces their action, and Person B says "I'm sorry, but I don't think you can do that. The rules don't work that way."