Each of the Siege cycle cards in Fate Reforged (Citadel Siege, Frontier Siege, Monastery Siege, Outpost Siege, and Palace Siege) has at least one triggered ability based on the turn structure.
Most of these abilities are fairly intuitive and cause little confusion during games. Only one of these, Monastery Siege, has an ability that triggers during your draw step–which is noticeably different from the others.
What makes this ability different is that there is a turn-based action that happens at what is (to many players) the same time as the trigger! The rules for the draw step tell us that there is only one proper way to handle this. Because turn-based actions do not use the stack, and the draw for your turn is the first thing that happens in the draw step, players do not receive priority and cannot play spells or abilities until the card draw is completed.
This means that draw step triggers like that of Monastery Siege will trigger, wait for you to finish drawing your card, and then get placed on the stack when you receive priority. So the end result is essentially “Draw, Draw, Discard” (rather than the much worse “Draw, Discard, Draw”).
This is good for you (as the controller); it means that even if you start your turn with zero cards in hand, you can still make a decision of what to discard for the second part of its resolution. This gives you control and choice–two things any blue player likes!
Today’s Rules Tip written by David Hibbs, L3 judge from Texas, USA