I think I've gotten the wrong end of the stick when it comes to what and when the DM should be calling for rolls when the party is exploring a dungeon.
Picture your typical D&D dungeon crawl. There's winding passageways, a handful of monsters on the prowl, one or two traps and a couple of secrets. My party, understandably, wants to move stealthily, keep an eye out for traps, and watch for secrets. We're playing in roll20 with dynamic lighting on, so they can only see a few squares in all directions, making travel treacherous.
As it stands I end up having them advance a few squares at a time, calling for a new perception check every time they find a new passageway, asking for stealth checks every now and again and having the rogue roll to look for traps each time they wander down a new hall.
This feels clunky, repetitive, and subject to goblin dice. The more they roll, the more likely it is someone will fail badly enough to be spotted by a monster or fall prey to a trap. However, running the entire dungeon on a single set of rolls seems to be against the whole spirit of dungeon crawling; why bother to explore a dungeon at all when a single roll has determined your fate?
I'm aware of the rationale behind long empty hallways in premade maps. In an ideal world you'd design a dungeon crawl that was only rooms, and parcel out your checks per room. But what about a cave system? There's no "rooms", per se… the whole map IS long, possibly empty "hallways". Sometimes you really are trying to navigate a large area with no obvious beginning or end.
I'm sure I'm missing something here… when, and how often, should players be rolling when dungeon crawling?
Best Answer
Passive checks are your friend
First, you can probably replace nearly all of your checks with passive perception (PHB 175):
This is usually done for perception, but you can also employ these for things like stealth as well. Passive checks let you automatically deal with all of those... passive rolls.
Only call for rolls when they matter
DMG 237 sums this up nicely:
Parse your dungeon crawl into specific scenes
You can avoid repetitiveness by clearly delineating the dungeon crawl into individual scenes. You allude to this issue when you talk about a dungeon that's only rooms. Basically, instead of thinking of the dungeon in physical terms, you should think of it in game scenes, and gloss over the unimportant parts.
For example, in a dungeon crawl I've run in roll20, sometimes I will just reveal a hallway or an empty room and say "there's nothing in here". Likewise, I don't move avatars or reveal areas on the map until it's actually relevant--I only use the map when the map is necessary. Doing so saves a lot of time that would otherwise be wasted rolling dice for no good reason. You can still create a sense of tension by throwing in a handful of red herrings, too.
Once your dungeon is set into scenes, you can make scenarios that matter. Instead of having your players stumble through a dark cave, rolling along the way, you can say "You grope through the darkness for a time, making good progress. In the distance, you notice the glow of a campfire...". You might notice that movies do this a lot: a character might be navigating a cave or dungeon, but viewers don't see all of it--only the parts that are somehow significant.
By viewing your dungeon as a series of important scenes, you can make every die roll somehow significant, and therefore streamline your dungeon crawl.