Magic the Gathering Ruling?

Any time you would be doing damage to the planeswalker's controller, you can choose to redirect that damage to the planeswalker. This includes combat damage and damage from spells. Whenever the planeswalker takes damage, loyalty counters are removed equal to the damage done. When there are no loyalty counters left, the planeswalker is sent to the graveyard.

Also, the planeswalker is a permanent, so any card that would destroy a permanent or remove it from the game will help you out as well.

Well, dealing with planeswalkers is troublesome. There are very few cards in standard that can nullify them (such as oblition ring), in extended we have vindicate.

Planeswalkers are not creatures, therefore any spells that can target a creature, can not target a planeswalker (shock, psyonic blast, etc).

A planeswalker will take combat damage if its controller decides to assign some combat damage to it (but its up to he planeswalker controller, not the attacking player).

Finally they can not be targeted by cards that give -x/-x effects such as nausea, sudden death, etc.

here are the rulings for the new card type "planeswalker":

http://www.wizards.com/default.asp?x=magic/rules/p...

Remember, not all creatures have to be "destroyed" by doing damage....removing them from the game can be very effective!