Argthtjtr

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:

1. 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.




2. 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

Kobold Fight Club is an excellent tool for scaling encounters on the fly, and I use it constantly. The main trick in your arsenal is to add and remove enemies, rather than changing the stat blocks.

For example, if I set KFC to account for 4 level 5 PCs, it tells me that 5 gargoyles are an appropriate challenge for such a party, just barely a Deadly encounter. So let's say your module has such an encounter and your PCs are actually level 6. According to KFC, you'd need to add 2 more gargoyles to scale this encounter appropriately. If they're level 4, you'd need to scale back to 3 gargoyles.

Another thing you can do is bump the monsters up or down a tier. A lot of the monsters in the game have weaker or stronger counterparts. For example, a Gargoyle is an elemental. I can use KFC quickly to find all the elementals, and it looks like an Earth Elemental is CR 5. So if the PCs are level 7, for example, I might swap out two of the Gargoyles for Earth Elementals. If the PCs are of a level a lot lower, I can try swapping out for Mud Mephits. The tool tells me quickly what number of enemies I'll need to challenge the party I have.

If you're finding that your players are having a really easy time with the enemies you throw at them, try just giving the enemies more hit points. For example, a Gargoyle normally has 52 hit points, with hit dice 7d8+21. Just giving them 77 hit points instead makes them a lot tougher. The beautiful thing is that your players have no idea how many hit points your monsters have, so you can adjust this as late as you want in response to the resources the PCs actually have at their disposal. This obviously works the other way around, too. To make an encounter easier, just take away some of the monsters' hit points.

Apocalisps answer provides a great link and some excellent suggestions. I'd like to provide some additional material that has helped me tremendously in the past:

https://theangrygm.com/series/custom-monster-building/

These two links in particular are great at explaining the systems you're seeking to play with:

https://theangrygm.com/monster-building-201-the-dd-monster-dissection-lab/

https://theangrygm.com/monster-building-202/

Although these blog posts are mostly focused on homebrewing from scratch, they contain an excellent breakdown of the balance mechanics of 5e. Even if you're not making your own monsters, this analysis will help you get a feel for challenge rating and monster/encounter difficulties. Knowing the math behind the fluff allows you to play with these things without breaking the system.

To avoid copy-pasting the entire treatise, here's a summarising quote from the end of Monster Building 201:

... you have NO CONTROL over proficiency bonus. It is determined
entirely by the Challenge. And it is always added to certain things.
[...] Challenge should be the first thing you pick. Because Challenge
also tells you where the HP, AC, Damage, and Attack Bonus have to
fall. So you pick your Challenge with care.

BUT, now you also understand that Challenge has two components.
Offensive and Defensive. And Offensive Challenge starts with Damage
and then is modified by Attack and Save DC. And Defensive Challenge
starts with Hit Points and then is modified by Armor Class.

[...]

MOREOVER, you also understand what you CAN Tweak. You have the LEAST
control over Attack Bonus. Why? Because it’s mostly Proficiency
Modifier and if you tweak the Ability Modifier, you’re also f$&%ing
with the Damage. And maybe the Armor Class if the creature is using a
Finesse attack and the equivalent of light armor (natural or
artificial). With manufactured weapons, you trade damage for potential
Armor Class as well. Two-handed weapons do the most damage but they
cost you a shield.

MEANWHILE, traits, special abilities, even movement modes affect the
Challenge of the creature. Which means you’ve got to take them into
account. Giving a monster Nimble Escape seems like a neat way to make
an assassin, but remember that creature is boosting its Armor Class
and Attack Bonus by hiding every round. And that means, overall, the
Challenge of the creature is two levels higher than you think it is.
And now you should be able to figure out why I can say that so
absolutely. Nimble Attack [sic] outright increases the Challenge of any
creature by two levels. Every time. Work it out. Check DMG 281 and
think through the numbers.