So I've just read about Keyforge. It's intriguing, but I don't think I'm fully understanding it and the FAQ isn't specific enough to help. As a result, I have some questions.

1. How different is every deck? My understanding of it is that every single deck printed and packaged is different. That would be a nightmare to balance so presumably they share the same overall pool of cards and the same card can be found in multiple decks? In which case, how much variation is there? Are we talking decks being pretty much identical except for a couple of changed card ratios or a different sub-boss card, or is there little to no repetitiveness between decks?
2. Am I allowed to create or modify my own deck in any way? I'm reading that the answer is no, but in that case, how would such a rule be enforced? What's to stop me switching in a few cards from another deck to make mine better? And how do officials track this information? If every deck is different, they must either have a huge database of the serial number of each deck printed and which cards that deck contains? Outside of the preliminary deck check, what's to stop me changing my deck when it comes to a duel? How would my opponent tell if I was using a custom deck? How would I tell if my opponent was?
3. What's the level of power variation between decks? We can sit here all day talking about how skill based the game is, but it's a matter of fact that some cards will be better than others and thus one deck will be better than another. Does that mean there's a possibility of me paying however much for a deck to open it and find out it's absolutely unplayable? On a similar note, does that mean I have no way of knowing whether the deck is of a style I'm looking for before I open it?
4. How is balance achieved? The thing I read said that they have things in place to deal with the possibility that any one deck is too good. What are those procedures? And when each deck is unique to a single person, how do they justify singling out that deck? Do they even need to when the majority of people attending any given event won't be playing against it?

1) There's a pool of 370 cards that all decks are created from. Each deck has 36 cards, made up of cards from three houses, averaging 12 cards per house.

2) Each deck has a unique back and name, with the name printed on the back and front of the card. So if you try to "sneak" cards in, finding the card that doesn't belong to the deck is relatively easy. Decks are tracked via a QR code and serial number.

3) In theory, all decks are "competitive" but so far the sample size is a kind of small to fully answer that question. There are definitely super strong decks out there, but how dominant they are remains to be seen. All decks will be playable, but they are all blind bought at 10 bucks a piece. There is already a site online that will let you buy stating the three houses you want, but aside from that, you are buying a procedurally generated playable deck of unknown power.

4) There's a handicapping system called Chains. I suggest reading the rulebook to understand how it works in casual play. How it will work in Organized Play has yet to be seen.

1. FFG has stated there are a possible 104,000,000,000,000,000,000,000,000 different decks. (In Short Form or American numbers that's one hundred and four septillion, in Long Form or European numbers that's one hundred and four quadrillion. FFG seems to be using the European naming convention in its promotional literature. Not sure why...) Given the total deck pool it is somewhat unlikely that you'll ever see two decks that are close.

2. Given that each card in a deck has a unique back a lot of people are wondering if FFG will allow or possibly require clear sleeves. The deck's name does appear on the front of the card as well, but in pretty small text which could easily be missed. This is one case where clear sleeves might make cheating harder than opaque.

3. No deck should be unplayable. They supposedly have an algorithm to build the decks with the hope of getting all decks close, but there will definitely be decks that are easier to play well. There does seem to be a bit of a rock/paper/scissors effect where one deck might be really good again certain decks but also weak against others. Time will tell. Also, decks are only $10 USD, so to many the risk is not that high. How long does it take to get $10 worth of playtime out of a deck? Possibly as long as it takes to figure out if you enjoy playing it.

4. Balance in casual play is similar to systems set up for golf or go by using a handicap of chains, which just reduce your draw ability for a certain number of turns. There are lots of suggestions for Organized Play depending on what sort of tournament is being played.

Re: 3, I bought a deck today at the pre-launch that was horrible.

It was Mars, Sanctum, Logos. Not enough creatures in general, and only 4 Mars creatures (1 of which was John Smyth), with a Brain Stem Antenna for a rare. Combat Pheromones despite astronomical odds against actually having 2 other Mars cards on the board.

2 Protect the Weak, which even on one of the two Staunch Knights, on a flank, generally couldn’t keep it alive through the entire resolution of One Stood Against Many. 2 Terms of Redress. Inspiration. Squawker.

I guess it was sort of supposed to hope for Numquid the Fair, but in 2 games (the second of which I lost against one of the precons from the starter), I didn’t draw it.

After the second loss with that deck, my opponent asked to look at it and with the cards laid out it was pretty clear it was a bad deck. Imagine my surprise when he offered to trade his (quite good) deck for it. Apparently he likes playing bad decks and seeing what he can do with them. He didn’t have to ask twice!

The QR code on each deck will be scanned into the app at each tourney, then the decks will be tracked that way. A certain deck wins enough tourneys, it becomes "ascended". Ascended decks can not be used at official tourneys. There may be tourneys later on that you can only play in with an ascended deck.

All of this is what they told us to tell people when we were demoing it at gen-con. It keeps balance in OP by not allowing a super strong deck to keep smashing tourneys. You win a few, you have to find a new deck to play. Since decks are only $10, its not like you are out a lot, and you've probably gotten at least that much out of it if you have won multiple tourneys with it.