While running dungeon crawls in D&D 5e, I have found that balancing encounters often takes far more prepwork than the storyline does. It's necessary to account for all the exp players may receive so that even completionist parties don't trivialize the boss, and so that noncompletionist parties can play through and have a rewarding final battle.
One step I've taken so far to reduce the issue is to make the experience reward constant so I can freely adjust hp and the amount of monsters on the fly. Sometimes I even substitute statblocks. While it's generally effective, it isn't always a clean substitution and sometimes results in having to add traits to a weaker monster.
It doesn't seem documented anywhere, but is there a quick system to take an existing module encounter and rebalance it during a session? If it's possible to quickly scale monster abilities to the party (within a minute or less), or put the module's monster traits onto a party-appropriate set of stats, it would make encounters much easier to adjust and speed up prepwork to allow more focus on effective worldbuilding and narrative preparation.
What system can be used to generate a level-appropriate version of a monster the party may be way under or overpowered for?
A couple of side notes:
To clarify "completionism", I've had some parties pursue every possible experience point in the module, methodically exploring and mapping everything and keeping thorough notes. Parties like these often end up 1 or 2 levels above a boss; enough to change the following encounters difficulty significantly. There are also "noncompletionists" who don't follow enough sidequests and face a boss who very nearly wipes them because they haven't quite collected enough experience, especially when they find creative ways to circumvent module expectations. I've also had cases where a party is smaller or larger than intended for the module. While Wizards of the Coast (WotC) generally provides good advice and adjustment options, I'm not always running WotC modules.
To clarify my levelling and experience awards, I award levels on return to town for all day sessions with my home group, and the few times I host online, I reward after the session. This sometimes means that adjusting encounter difficulty while they're partway through a string of encounters is necessary. Party compositions also sometimes yield unexpectedly good strategies that require a bit of counterbalance to keep the module challenging without punishing the player's creative new tool. I also keep experience constant despite adjustments; a "Hard" encounter for one party may be easy for another, so giving the "Hard" experience and adjusting as necessary to fit the party is my approach.
As such, although most of my balancing prepwork ends up in the correct ballpark, it would minimize prepwork and address any issues that I notice brewing if there is a method to adjust monster and encounter difficulty during a session.
Given a party that is either:
- a few levels outside of the module's expectations
- hitting a few levels above their weightclass
How do I adjust an encounter as written? Particular interest in cases where:
- the monster is already at the top of its hierarchy and no "improved" statblock (i.e. no party or story appropriate goblinoid) exists.
- the monster is unique to the module being run and has no close equivalent in official or well-known sources