Lobber Crew reads:
Kingdom . Action: Sacrifice this unit to force an opponent to sacrifice a unit he controls, if able.
When I use this action, it creates a LIFO stack (or can be added to one already in progress). So, does the sacrafice happen during "payment" to add to the stack? In other words, do you have to sacrifice the unit to add the action to the stack or just announce you are adding the action to the stack then sacrifice the unit during resolution of the stack?
This also brings up Brutal Offering which reads:
ACTION: Sacrifice a Unit. If you do, deal X damage to each unit in all Battlefields, where X is the sacrificed Unit's Power.
In this case it is my understanding that you sacrafice the unit during resolution but I could be wrong. I do feel that whatever happens for one should happen for the other I just cannot figure out which way it should be.
It is also important to note that if you do not sacrafice the lobber crew as payment, the you could add the action over and over to the current stack as you see fit so that no matter what your opponent does, the lobber crew will resolve first (which means your opponent cannot steal one of your units in order to sacrifice with take captive! or grasping darkness.
, but neither the card nor the rules say that one part of an action's effect is a payment and another part is not. It all happens when it gets it's turn after waiting in line. Which could be why they installed Forced effects in the first place: to make sure certain things aren't preempted by response actions.