When I go to Gladiatorial Arena, Qualifying Round, I'm not given the chance to look at my party and deckbuild. It just goes straight to the first battle's descriptive text, then the fight.
The game used to take you to deckbuilding before every adventure, but our alpha testers (and devs) thought it was a bit pointless, so we cut it to streamline the flow.
I see. The problem with that, however, is that your main "deckbuilding center" (the Keep) is currently at one point on the map, and if you're out adventuring you have to drag back to it in order to enter it. And at least in my case, if I'm out looking at adventures then THAT'S the time I'll realize I need to deckbuild: "Huh, yeah, this slime-heavy module would be a good place to level-up my secondary party; better completely reverse my anti-skeleton build." Does the deckbuilding screen at least appear if it's the FIRST time you play the module? If anybody says "Nah, you don't need even a cursory reminder of what you have equipped the FIRST time you do a module," then . . . might as well not bother to put useful information in the module description because apparently you don't get to use it. (This seems to have wedged itself in "feedback forum" territory.)
You know technically you also get access to deck building by visiting Shop/Chest places, in fact I can't remember the last time I actually use the keep to change my deck.
Yes, I am aware of shops. (It's on the long list of "Is this worth it to mention in my post? By establishing 'yes, I already thought of that, and it doesn't change my point,' will I actually accomplish anything or will I just make my post longer and reduce the number of people who bother reading it?") Given the cramped quarters in a shop, and given how many different items I have in each combination of slot and [insert primary sort level here, such as Talent], I can't even see enough of my inventory in a shop to make informed choices. This situation will only get worse when Blue Manchu adds further loads of items for other slots. I can't remember the last time I used a shop screen for any item-swapping other than "I happen to remember the name of the item or small-quantity card I want, so I can type it right now."