I think the problem is that "random minor bonuses" is, in many way, equivalent to "piles of new free utility powers".
Now, most of the time, players won't control what card they drew and whether it is useful or not - so nothing gamebreaking there.
The bigger issue is if someone has built a deck of effective, reliably useful rares. All my attacks are "Mind over Metal" - letting me always have my attacks target Will instead of AC. We've got daily item powers or encounter powers that do that sort of thing - but now players can basically get it on nearly half their attacks, for free.
Various Defense and Tactics cards can give you a "Stroke of Luck", which is a free reroll - usually when something bad has happened to you, but that includes stuff like provoking OAs, which you can set up. So suddenly a player is potentially generating free rerolls every other round, and a reroll is at least equivalent to an encounter power, if not a daily.
Will players with a handful of random Fortune Cards unbalance the game? Not really. But ones with an optimized deck will have a pretty direct increase in power level. Now, that is not inherently a bad thing.
But the players in my group are already pretty effective - no one really needs a power boost, especially one that adds even more fiddly bits to the game.
I can see uses for Fortune Cards outside of the way WotC is presenting them. But the default use for them just isn't something I have any need for. It might for others, and that's fine, but I don't think one can really declare them as having no impact on the game, either.
Now, most of the time, players won't control what card they drew and whether it is useful or not - so nothing gamebreaking there.
The bigger issue is if someone has built a deck of effective, reliably useful rares. All my attacks are "Mind over Metal" - letting me always have my attacks target Will instead of AC. We've got daily item powers or encounter powers that do that sort of thing - but now players can basically get it on nearly half their attacks, for free.
Various Defense and Tactics cards can give you a "Stroke of Luck", which is a free reroll - usually when something bad has happened to you, but that includes stuff like provoking OAs, which you can set up. So suddenly a player is potentially generating free rerolls every other round, and a reroll is at least equivalent to an encounter power, if not a daily.
Will players with a handful of random Fortune Cards unbalance the game? Not really. But ones with an optimized deck will have a pretty direct increase in power level. Now, that is not inherently a bad thing.
But the players in my group are already pretty effective - no one really needs a power boost, especially one that adds even more fiddly bits to the game.
I can see uses for Fortune Cards outside of the way WotC is presenting them. But the default use for them just isn't something I have any need for. It might for others, and that's fine, but I don't think one can really declare them as having no impact on the game, either.