Card Text:
Change of Target
Only usable if this minion is blocked, before block resolution.
Unlock this minion, and the action ends (unsuccessfully). This minion cannot perform the same action again this turn.
the blocking minion don´t lock because the action ends before the block resolution (when he was(will?) became tapped, sorry english is not my native language)
David Resende - Prince of Teresina
Always include card text when asking for specific clarifications.
Change of Target
Only usable if this minion is blocked, before block resolution.
Unlock this minion, and the action ends (unsuccessfully). This minion cannot perform the same action again this turn.
So clearly
a) the acting minion is unlocked
b) there's no mentioning of status change of the blocking minion, so he stays in the status he had before the block attempt
Also:
Is played after a minion successfully blocks, before the blocker is locked and combat begins. It cannot be used if the action is ended without being blocked. [LSJ 19980224][RTR 19991206]
<INSERT CLEVER QUOTATION HERE>
Also,
> rulebook wrote:
> If the action is blocked, then any card played to perform the action is burned and the block is resolved with these two simultaneous consequences: the blocking minion is locked and enters combat with the acting minion (see Combat). If an effect ends the action before the block resolution or one of these two consequences (such as entering combat), neither consequence occurs.
>
Prince of Paris, France
Ratings Coordinator, Rules Director