Bioshift

Instant

Move any number of +1/+1 counters from target creature onto another target creature with the same controller.

2013-01-24:
To move a counter from one creature to another, the counter is removed from the first creature and placed on the second. Any abilities that care about a counter being removed or placed on a creature will apply.
2013-01-24:
You decide how many counters to move when Bioshift resolves.
2013-01-24:
If one of the two creatures is an illegal target when Bioshift tries to resolve, or if the creatures are controlled by different players at that time, no counters will move.