FASA Games, Inc.

Ok, it's the first time I have to deal with Vine Armor (4th edition).
The description make the rules a bit ambiguous.

It sais it improves the use of Wood Skin. So let say I wish to activate both Wood Skin (WS) and Vine Armor (VA).

a) I roll Tou+WS ranks+VA ranks and spend a recovery test. The Result is both the WS effect and the VA effect.

b) I roll Tou+WS ranks+VA ranks and spend two recovery tests. One for WS and one for VA. The Result is both the WS effect and the VA effect.

c) I roll Tou+WS ranks and spend a recovery test to activate WS. THEN, I roll Tou+WS ranks+VA ranks and spend a recovery test to activate VA.

d) I roll all my Karma left but add only the odd results. Then I multiply by the square root of pi and I use this result to interpret my talents.

from the FASA discord I bring a quote from Morgan Weeks, who is one of the main writers for Earthdawn (and in particular tends to be in charge of writing rules):

"Two Recovery Tests total, one test, spend everything before the test is made."

(this quote is from a little over a year ago, but as the talent has not been rewritten the answer should be the same).

edit: from your list, I'd say that matches up with b, although d could always be fun

Thanks!