Increased Hand Size

If a Master Card increases your hand by +1, do you immediatly draw an extra card after drawing to replace the Master Card? I guess I'm asking if you immediatly draw extra cards after you play cards that increase your hand size.

Granted that your Master is not Suddened/Washed, yes. The effect is immediate. Advocate of Good-looking Deck Posts pulledfangs.blogspot.com :vtes: Manila V:tES

You should ALWAYS have a number of cards equal to your handsize. There are a few cases when this doesn't happen: - when you are pending to replace a card (in the "as played" window) - if you have a card which replacement is delayed (Wake with Evening's Freshness, Mirror Walk, ...) These cards actually reduce your handsize. It is also important to know that if you contest the Elder Library, you don't get a (very) temporary +1 handsize. It gets contested immediately.

likewise, if some card gives you -1 handsize, you must immediately discard a card to match your new limit (not wait until your next card play)