Forgive me for perhaps not understanding my native language that well.
That would explain my struggles with Portuguese I suppose.
Perhaps you assumed something by my current residence, but I spent the first 22 of my 24 years of life in America, am a native speaker, and only moved to Brazil to be with my wife. I do hope that I have, at least, a "basic grasp of English," or English as a whole may have changed beyond recognition in the past 10-15 years.
Instead of insulting you as you have to me (and you thought the suggestions last week were belittling the TO's?) I will simply show you why you are wrong.
If I start the tourney, match 1, duel 1, I am in a duel, and I will not be able to change my deck between any two duels according to the rule, as written.
So:
Match 1, duel 1 to match 1, duel 2. I cannot change because I am between duels.
Match 1, duel 2 to match 2, duel 2. I cannot change because I am between duels.
Match 1, duel 2 to match 1, duel 3. I cannot change because I am between duels.
Match 1, duel 3 to match 2, duel 1. I say I cannot change because I am between duels. You claim that in this situation, I am NOT between the two duels, when clearly, I am between two duels, but these duels are just in different matches.
Now I just have to question why you would be insulting on the subject, or attempt to be. Even if I were not an American, and even if I were Brazilian, I can't imagine a jab at someone's English was in order in the slightest, particularly when it is painfully obvious that a tourney is a series of duels ("A match consists of up to 3 individual duels. The player who first wins 2 duels, is the winner. Winner goes on to the next round and the loser is eliminated from the tournament"), and as such, there is never a moment in the tourney that you are NOT between duels (and can access the deck management area to change a deck).
Forgive me if this was just a bit too long, but I don't take well to being insulted, and I DO feel quite insulted when someone tells me that I do not have a basic grasp of my native language.
Change it or don't; I have no motivation to participate in a tourney run by someone attempting to be offensive and inflammatory, anyway.