Descent Into Avernus Campaign Rules
Unless otherwise stated, RAW is followed as closely as possible.
Character Creation
Races
All Races from the Player's Handbook and Monsters of the Multiverse will be available.
Races from the PHB will have their ASI bonuses changed to match the Monsters of the Multiverse versions (I.e. +2, +1 or +1, +1, +1)
All races from the PHB have their base speed increased to 30.
No race has Sunlight Sensitivity.
Races with Magic Resistance only have advantage on saving throws against spells, not "magical effects."
You'll be starting at 1st level with standard starting gear.
Background Feat Replaced With Starting Feat
Rather than a background feat such as "Shelter of the Faithful" or "Wanderer," players will be able to choose from a list of starter feats.
- Actor
- Artificer Initiate
- Athlete
- Chef
- Durable
- Eldritch Adept (No Devil's Sight)
- Elemental Adept
- Healer
- Inspiring Leader
- Linguist
- Magic Initiate
- Martial Adept
- Metamagic Adept
- Poisoner
- Ritual Caster
- Skill Expert (No ASI increase)
- Skilled
- Tavern Brawler
- Tough
Available Content
- Player's Handbook
- Xanathar's Guide to Everything
- Tasha's Cauldron of Everything
- Monsters of the Multiverse
- Bigby Presents: Glory of the Giants
- Fizban's Treasury of Dragons
- Van Richten's Guide to Ravenloft
Everything else is case-by-case basis. If there is something specific you want, such as a background, subclass, or spell, run it by the DM.
Gameplay
Variant Encumbrance
Pg. 176 of PHB
Magic Backpacks and Quivers
As long as you have the encumbrance for it, one backpack, quiver, etc. will carry everything that you can.
Diagonals
Pg. 252 of DMG
Spell Point Variant for Sorcerers
(This is optional.)
See Pg. 287-288 of DMG
Renaissance Firearms & Explosives
The Pistol, Musket, Bombs, and Gunpowder, are available to players. However, Pistols have 2d10 damage dice and Muskets have 2d12 damage dice.
(Chapter 9 of the DMG)
Group Checks and Helping
Whenever someone attempts an ability check and someone wants to help, the helper must have proficiency in that skill or tool to grant them advantage on that check.
Additionally, when several people want to attempt a check after someone already has, it becomes a group check that uses the first roll as that player's part of the group check.
For RAW, see Pg. 175 of PHB
Crafting
Consumable items such as potions can be made over the course of one day of downtime. Non-consumable items can be made over the course of a week of downtime.
Spell Scrolls
Anyone can attempt to use any spell scroll with an Arcana check equal to 10 plus the spell's level.
For RAW, see Pg. 200 of DMG
More Difficult Identification
Pg. 136 of DMG
Mixing Potions & Scroll Mishaps
Pg. 140 of DMG
Powerful Build
Creatures with the Powerful Build feature count as one size larger for the purposes of grappling/shoving other creatures.
Owlbear Whisperer
You can target a monstrosity with spell that would otherwise only target a beast, provided the creature's Intelligence score is 3 or lower.
Combat
Grewhawk-ish Initiative
In combat, each creature rolls for initiative individually. Additionally, initiative is rerolled at the start of every new round in combat.
I have a module in Foundry that automates this process, so it doesn't slow combat at all.
For RAW, see Pg. 189 of PHB
Healing Surges
Once per short rest, players can use a healing surge as a bonus action. Additionally, a character regains all spent Hit Dice at the end of a long rest and one-fourth total hit dice at the end of a short rest.
For RAW, see Pg. 266-267 of DMG
Hitting Cover
Pg. 272 of DMG
Action Options
Climb Onto Bigger Creature,* Disarm, Overrun, Shove Aside, Tumble
Pg. 271-272 of DMG
* see below for a more streamlined "Climb Onto Bigger Creature" option
Climb onto a Bigger Creature
When you want to climb onto a larger creature, you can make a grapple check against a creature at least one size larger than yourself.
If you win the contest, you move into the target creature’s space and cling to its body. While in the target’s space, you move with the target and have advantage on attack rolls against it.
You can move around within the larger creature’s space, treating the space as difficult terrain. The larger creature’s ability to attack you depends on the smaller creature’s location, and is left to the DM's discretion. The larger creature can dislodge you as an action—knocking you off, scraping you against a wall, or grabbing and throwing you—by making a Strength (Athletics) or Dexterity (Acrobatics) check contested by your Strength (Athletics) check.
Resting
One D&D Exhaustion
The exhaustion from the PHB will be replaced with the following rules:
Levels of Exhaustion. This Condition is cumulative. Each time you receive it, you gain 1 level of exhaustion. You die if your exhaustion level exceeds 10.
d20 Rolls Affected. When you make a d20 Test, you subtract your exhaustion level from the d20 roll.
Spell Save DCs Affected. Subtract your exhaustion level from the Spell save DC of any Spell you cast.
Ending the Condition. Finishing a Long Rest removes 1 of your levels of exhaustion. When your exhaustion level reaches 0, you are no longer Exhausted.
For RAW, see Pg. 291 of PHB
Who Takes Short Rests? We Take Short Rests
Short rests are only 10 minutes, but are limited to two per long rest.
You Can't Sleep While Enemies Are Nearby
Long rests can only be taken in safe and comfortable places.