However we have to interpret it based on the most recent Comprehensive Rules and CRD available. They muddy the water significantly, especially with the playing the card entry and when effects take place. Based on the rule sets CURRENTLY IN PLACE, the answer can be seen in both lights.
This is very true, and for one, why I originally was believing your side of the argument.
The reason I changed my mind was because of this statement:
All cards do what they say, no more, no less.
...and can be further demonstrated in this statement:
I'd even go so far as to say that the wounds cannot be prevented is the most logical conclusion.
The point I'd like to make is this:
If this is all we're given, why try to go so far as to
rationalize a reason to fit a ruling that we are predisposed to? Yes, Decipher was sloppy with their wording and rulings, but that shouldn't give license to decide the rules or what they mean for ourselves...
Amidst the differing opinions about this card and whether it's an "action" or "effect", what "this" and "wound twice" really means, etc etc, what it boils down to is that we should just do what the card says.
1. Spot Gandalf (Cost).
2. Wound Gandalf Twice (Effect).
3. Discard two cards to prevent (an option to "prevent" the effect).
The effect is wounding Gandalf twice. There is no reason to open a can of worms trying to explain how this wounding really actually isn't wounding because of the fact that you have to resolve the card, etc etc...you just prevented an effect. It was two wounds...from the information we have, following the rule of doing what the cards say, you just prevented two wounds.
Draino's most recent response on the discussion thread are also very significant; I probably won't be moved on this opinion regardless of what MarcinS decides to do with the coding.
It just looks, based on the responses, that the argument for allowing prevention boils down to "the cards
should have read X instead, and Decipher was just getting sloppy, so we have to assume what they meant based on how we interpret the CR".
I'd much rather just do what the card says,
without any presumptions on intended meaning, instead