If an effect would create one or more tokens, it creates twice that many of those tokens instead.
If an effect would put one or more counters on a permanent, it puts twice that many of those counters on that permanent instead.
Whenever chaos ensues, until end of turn, whenever you tap a land for mana, add one mana of any type that land produced.
(01/06/2012)
Adding loyalty counters to a planeswalker in order to activate a loyalty ability isn't an effect, so those counters are not doubled.
(01/06/2012)
Any -1/-1 counters that are placed on a creature because of wither or infect are also not doubled.
(01/06/2012)
The chaos ability is cumulative. For example, if you roll twice in a turn, tapping a land for mana will cause two mana abilities to trigger.
(01/06/2012)
Effects that place a counter on a permanent include that permanent entering. For example, a creature that normally enters with one or more +1/+1 counters will enter that many +1/+1 counters on it. A planeswalker will enter with twice its starting loyalty counters.
