A few times during our games we have had the situation come up where the Wizard starts the game off with or during the game draws spells he can't cast.
Spells like Counterspell or Nulify. If other people are playing characters that don't have access to spells or can only get them randomly through the game, this can be quite frustrating and it really limits the Wizard.
My question is: Are there rules somewhere or do you have any house rules saying that you can discard a spell you can't cast to get another?