You don't have to have your entire Deck ready before the first Duel. In fact, if you only have a few select cards planned out by then, that's fine. Just build on it as time progresses. We'll also be Dueling a lot of NPC characters, which will be tempting to look at and go: "Ooooh . . . Imma FTK this freak." Try to resist doing this . . . all the time. Once or twice is fine. I have literally no restrictions as far as RNG. None. Unless someone tries to be overly repetitive or obnoxious in his/her strategies. Then we have some problems. But yeah. To start out, just make enough cards to last you one Duel, so maybe a quarter of the Deck to be safe.