Koth's Courier magic what does forestwalk do

[monto]

the card Koth's Courier has forestwalk ability, anyone know whats that do?

[Kenji]

Yep. Sometimes, there won't be reminder text for a given ability. In that case, you'll usually refer to the comprehensive rules document to help you out:

link: http://www.wizards.com/magic/comprul...s_20110204.txt

702.12. Landwalk

702.12a Landwalk is a generic term that appears within an object's rules text as "[type]walk," where [type] is usually a subtype, but can be the card type land, any land type, any supertype, or any combination thereof.

702.12b Landwalk is an evasion ability.

702.12c A creature with landwalk is unblockable as long as the defending player controls at least one land with the specified subtype (as in "islandwalk"), with the specified supertype (as in "legendary landwalk"), without the specified supertype (as in "nonbasic landwalk"), or with both the specified supertype and the specified subtype (as in "snow swampwalk"). (See rule 509, "Declare Blockers Step.")

702.12d Landwalk abilities don't "cancel" one another.
Example: If a player controls a snow Forest, that player can't block an attacking creature with snow forestwalk even if he or she also controls a creature with snow forestwalk.

702.12e Multiple instances of the same kind of landwalk on the same creature are redundant.

So, since Koth's Courier has Forestwalk, this means it is unblockable as long as the defending player controls at least one forest.

[monto]

What if he controls nonbasic land that males forest mana?

[Arix]

There's no such thing as "forest mana". Forests make green mana. Just because a land produces green mana, that doesn't make it a Forest. Only if it actually has the subtype "Forest" does it count as a Forest.