Here are the questions I have had while reading the rules or playing, and the answers I've come up with for my own play. I'm sharing them for the benefit of others, but they are in no way endorsed by the creator of Delve.
Q: You get 5 soldiers at the start, in your entrance square. Is this square a kind of Barracks? If so, is its limit 5? Or will the soldiers move to the first Barracks I build?
A: Unclear in the rules. I treat it like a free, first Barracks with a capacity of 10.
Q: When do I shuffle the cards I've drawn back into the deck?
A: Page 4 says "After you've resolved a card (e.g. drawn the discovery on your map, and dealt with any combat) shuffle it back into your deck." This could mean every turn and maybe more. That's kind of ungainly, so my ruling is that I only shuffle the deck at the end of a turn in which I have drawn an Ace. Note that I also use the deck for the d2/d4 "rolls" instead of rolling dice. So I go through a lot of cards.
Q: When Exploring, do I have to build a corridor to get to an adjacent cell?
A: It is a little unclear, but my impression is this, from reading pages 3 and 11 primarily: all adjacent cells on the same level (row) are implicitly connected. All cells above or below are not connected, by default, and require stairs. Stairs and corridors are free, but you can only build one per turn and it takes up the time you would have built a room (so it's stairs OR corridor OR room). So why would one even build a corridor? Well, on page 9 it says a corridor or drawbridge can be built over water, so you could use it to bridge a space. A corridor takes up a cell, BTW.
Q: Can I build in a cell I haven't explored?
A: Yes? Apparently that's how it works. You can build in an empty room or cavern or in an empty cell. I got this (still get this) wrong a lot and think I have to have an empty room to build in, but the rules indicate you can build in an "unexplored space" that "you haven't drawn in" and which "connects to at least one adjacent explored space."
Q: Which units can I recruit at the start? Which things need a special room?
A: The answer is, ALL units that you might recruit require a room to be built (or sometimes found) first. (The exception would be if you treat the initial cell as a free Barracks.) Here is the correlation:
- Soldiers and Gunners need Barracks
- Hounds need Kennels
- Clerics need a Shrine or Temple
- Mages need a Library
- Prisoners need a Prison (duh)
- Alchemists need a Lab
- Golems need a Golem Forge (which you find, not build)
- Cannons need a Forge
- Skull Dwarves need a Crypt (which you find, not build)