This look like a good idea if your player are metagamer. From your past stories they seems to be.
For storygamer, the one level by dungeon seems a better idea.
 

Sounds good. I would probably handwave it completely and give them 1 level per dungeon, but if it doesn't suit you, what you propose seems like a good idea.

But may I ask, why you would let them rest after each fight, if the players try to 'metagame'? I would simply punish them with patrols running into them depleting even more resources, and disrupting the rest altogether. Or even make the encounters harder and harder the more time they spend in the dungeon. They would eventually get the idea that a 5-minute workday strategy (aka gaming the mechanics) will get them killed sooner rather than later.

The 2nd Edition module Thoughts of Darkness is a good read if you're looking to make your dungeon crawls more exhausting for the PCs.
 

Looks like a good rule.

'Handwaving' seems better on the whole to me, though. If you want to optimise combat to maximise level-grinding, why not play a computer game in which that's the natural mode of play that's supported?

I suppose the problem - in computer or PnP - is that players expect to be 'paid' for every encounter.
 

The "milestone" system where everybody simply gets a level at the end of each dungeon has its problems. Players generally do what they are rewarded for, so everything which doesn't have a milestone, like outdoor exploration or side trecks becomes uninteresting. And in Princes of the Apocalypse there are a lot of connections between dungeons and non-linear gameplay, which doesn't work well with milestones.
 

I've not really had to get this gamist with XP awards with my (admittedly unusually RP focused group). I give out XP and say "you level or you don't level", the players update their character sheets with no commentary or "did we level yet" type questions.

Even when running much rules-heavy systems like Rolemaster XP I've never had an issue with my group metagaming to maximise XP, they investigate, explore, RP, fight and whatever else as the mood takes them.

I've been reading a lot of 5E DM advice of late and honestly, I'm slightly shocked at how much my group varies from the apparently very metagame-heavy/"play D&D like a computer game" mood I find in writing and playsession reports.

As for the proposed solution it sounds reasonable for sure. I've never liked the idea that there should be an average leveling speed based on encounters though, it's far too easy for players to skip tons of content (and thus XP). In my second session of running LMoP the group skipped about 2/3rds of the Redbrand hideout and surprised the boss without any alarm being raised - there's no way I'm penalising them for very cautious and coordinated stealthy gameplay...
 

Does it need to be combat encounters? We use a system where all players present receive a fixed amount of XP at the end of each session. Absent players receive less (about half). Actually its not XP, but its the same concept. This means that there is a lot less hassle for all involved regarding XP tracking.

Note however that we also are fairly RP focused and consider one combat in a 5 hours session a good amount over many years experience. Some games have no combat and occasionally more than one fight. I think we have come to this point in our games because many of us get satisfy out min/max, combat focused urges in computer games, which do them generally better and enjoy the social and unpredictability aspect of actual role playing.

 

Here's what I'm trying to do with 5e now:
- less combat encounters, only big and important scenes
- short rest is 4-8 hours. You need conditions of a city and at least some medical treatment to actually restore HP. When players decide to take a short rest, time moves forward considerably, so any immediate actions (chasing bad guys, tailing kidnappers, running to the rescue etc) will become unvaialable after rest, and party will have to seek different, probably more difficult paths.
- long rest is 3-7 days of uninterrupted leisure and debauchery. Basically when players decide to rest, the time moves forward so much they effectively concede all time-sensitive tasks. So it is a big decision story-wise.
Fells gritty, tense and somehow pretty plausible. We'll see how it turns out in the long run.
 

Note however that we also are fairly RP focused and consider one combat in a 5 hours session a good amount over many years experience.

My group is far more combat oriented. And Princes of the Apocalypse is an adventure which basically leads the group through 13 dungeons filled with monsters.
 

Are you going to tell your players about the xp adjustments ahead of time? That is, are you using the bonus xp system as a carrot to encourage them not to rest after every fight? Do you think they will resist you changing the leveling system for the adventure? ... is that something that they trust you to do to make the sessions more enjoyable or is it something you decide to do regardless of their personal opinions because it is your right/duty as the GM?
Finally, have you made any plans if they decide to take constant rests and over time end up still at level 4 going into a level 8 or 9 dungeon? I am curious how this will all turn out.


 

Yes, of course I am going to tell them. They already had a bonus to combat stats for not resting in 4E. And as it is a pure bonus I don't imagine they will object. If they decide to go for less xp, I won't change the dungeons, but I would give them opportunities to do side treck adventures to catch up.