First I want to make clear you in no way need to change the game of D&D. Adjusting the game rules is optional. If you’re a new DM or have a difficult time holding the rules in your head (no judgment, there are a lot) go ahead and stick to the default rules.
Here are the official, published Wizards of the Coast options that may affect your worldbuilding.
This is the number one way to marry your worldbuilding to each PC. Add, alter, and remove background options to align PCs to your game world. Be mindful of custom background features and how they might be over/under powered. You can find guidelines to customizing backgrounds on DMG, 289.
Downtime activities can be a powerful way to emphasize in-game time passing. The downside is most downtime activities take considerable time. You’ll want to slow how fast the threats move in your world to compensate.
Downtime activities reinforce options like slow natural healing and gritty realism rests. These time dilating options give characters plenty of time to complete downtime activities.
Some options are definitely more potent than others. Consider trimming the list of what options are available by location and by the rules of your world. You can find downtime activity options in the PHB, DMG, and XGE.
The core assumption of D&D is heroic fantasy. The player characters are better than average people. At its heart D&D engages power fantasy. And nothing ruins a player’s power fantasy faster than taking that power away.
But, this can be a powerful tool if you’re wanting to run a darker, grittier game. You’ll want to get the players on board with these options before doing the groundwork.
You might consider rules system that better focuses on the psychological then D&D.
Surprise! Feats are an optional rule! You would never know considering how it’s treated in the official D&D publications. It’s the baked-in option and assumed for every game I’ve run across.
Consider what feats you want to add, alter, or remove with how it fits in your world. All feats are not created equal. Consider a rogue who has the Dungeon Delver and Observant feats.
Advantage on rolls to find secret doors
Advantage on saving throws versus traps
Resistance to trap damage
Travel at normal pace while searching for traps
+5 Bonus to passive perception and passive investigation scores
That rogue is going to be a thorn in your side when the party enters a dungeon. The rogue dramatically reduces the impact of dungeon secrets. It may push you towards a combat heavy, meatgrinder combat approach to dungeons.
More importantly what’s passive investigation? The idea that pops to my mind is when a bored person (usually a child) starts messing with something as a fidget.
“I’m not really looking for traps on this door, can I use my passive investigation instead?”
Magic Item Availability
The core assumption of Dungeons and Dragons is that magic items are very rare. The most common magic items are consumable like healing potions and spell scrolls. In the DMG the starting equipment doesn’t include a magic item until level five.
If you fill your game with magic items the player characters will be more powerful than their level suggests. Powerful magic items may even make some of your challenge’s trivial.
Reducing the amount of magic items in your game has much less consequence. Fifth edition continues the assumption that magic items are rare. PCs can’t buy magic swords at the corner store. Fifth edition’s emphasis on flat math downplays the necessity for a PC to have +3 armor at X level.
The major challenges of a low magic game:
You’ll need to keep your martial PCs from falling behind in the combat curve. You’ll also want some way to for the PCs heal in combat.
Consider a consumable blade oil that can be applied to a weapon or X number of ammunition. The blade oil functions as the Magic Weapon spell.
Consider making the Healer feat a function of the healer’s kit. It’s scaling, non-magical healing.
The Healer feat is WAY more powerful than Cure Wounds and it scales. At 20th level it provides 1d6+24 HP as an action that doesn’t take a spell slot. I’m currently playing a cleric and it is primo. Imagine your cleric using spells for buffing and damage instead of healing.
Altering the way D&D’s short and long rests work isn’t the worst idea in the world. One of the drawbacks of the 5e rules as written is a short rest is one hour. But any situation the PCs are safe enough to rest for an hour, they’re safe enough to rest for eight hours. This short changes classes that recharge abilities on a short rest.
The Epic Heroism has the PCs ready to fight with every conceivable resource every fight. So if you want a game with fewer but more epic set piece battles this works well. But you won’t be able to whittle down the party’s resources over time with small skirmishes.
On the other end of the spectrum is the Gritty Realism variant. Non-magical hit points are hard to come by and resting takes a long time. Don’t be surprised when the players are gun shy after a moderate battle. Their abilities, spells, and hit dice are a limited resource. They don’t know when they’ll be able to take an uninterrupted extended rest of one week.
Running many, small combat encounters harries the party and makes them feel like they’re always in danger. It will also help your PCs better manage their resources. They’re more likely to rely on cantrips and weapon wielders to pull them through a small fight. Only dipping into spell slots when things turn dire. Fleeing combat is also a more recognizable strategy for the players.
Healer’s Kit Dependency
Slow Natural Healing
Only one option presented in the DMG is actually helpful to the players. The Healing Surges variant allows PCs to heal themselves in combat.
In fourth edition everyone had access to the 5e Fighter’s second wind ability. It wasn’t good healing, but if your cleric was on the other side of the fight and you didn’t have a healing potion… one hit point was better than unconscious.
If you plan to run a game where healing magic is rare and reduced natural healing this would be a good option.
Healer’s Kit Dependency is a do-nothing option. It only ensures the group will carry at least one healer’s kit per PC. The cost is negligible once the characters have a few levels under their belt. Unless you’re tracking encumbrance at the granular level it has no effect.
Slow Natural Healing is a variant that creates a situation where the party wants to take multiple long rests in a row. The big question from a DM point of view is how do you make that entertaining? Extended rests are a good way to promote role play between player characters.
In the variant RAW, Lingering Injuries could be devastating to a game. If you roll a lot of crits behind the screen a PC can be easily hamstrung. Lose a hand and the two-handed melee or ranged focused fighter loses functionality. This variant is brutal when piled on top of being KO’d in a combat encounter.
As a consideration many conditions in this variant can only be cured by Regenerate, a 7th level spell. That requires a 13th level cleric. If you’re starting a campaign from level one, avoid it. Or you could spend the time to tweak the variant’s conditions to make them more surmountable at low level.
Don’t add advanced technology to your world, just don’t. The crossbow expert and sharpshooter feats already push power to ranged combat. Don’t introduce even more powerful ranged combat weaponry into that mess.
If you’re deadset on adding one of these options consider a different rules system. It will serve you better in the long run.
Custom Content & House Rules
If you’re looking to involve custom content or house rules in your D&D campaign there are a few things to keep in mind.
Give thought to how changes will affect gameplay.
Is Dungeons & Dragons the best rules system for the game you’re trying to create? D&D is built for heroic fantasy games with a heavy emphasis on combat. There may be a different rules system better suited to the type of game you’re trying to make.
Make your players are aware and understand the houserules BEFORE they make characters.
And don’t forget this golden rule:
Limitations over Limitless
“I believe more in the scissors than I do the pencil.”
– Truman Capote
My house rules and variants I’d like to use and why
If you’re going to include Common, I don’t even know why they include languages in RPGs. Also, the implementation of a universal language is silly.
There is no universal language.
Literacy isn’t fundamental. People have to be taught to read and write. PHB, 123 shows what script is used for each language.
You don’t have to search long on the internet to find someone talking about how you should avoid racial monocultures. But we’re supposed to believe that all elves speak the same language? Humans don’t. Language is regional, not racial.
Backgrounds are great and they can add a lot to your game. They’re a great way to get player buy-in on your worldbuilding when its married to the PCs right out the gate.
I want immediate player buy-in. I want to help my player’s backgrounds to feel grounded in the world.
Always Passive Insight & Perception
Making Insight and Perception a passive defense (like AC or 4e’s saves) helps keep the game flowing.
It cuts down on players repeating checks until someone rolls high enough for them to feel certain they aren’t missing anything.
Different time rules for Dungeon, Travel, Town.
Short Rest – 1 hour
Long Rest – 8 hours
Short Rest – 8 hours
Long Rest – 24 hours
Short Rest – 24 hours
Long Rest – 1 week
This makes travel more strenuous on the party. They’re less likely to go nova on encounters while traveling or in town.
Here’s a quick history lesson, pirates didn’t bury much treasure.
They gained money quickly and spent it just as fast. My assumption is adventurers operate in the same feast or famine mentality. You do a couple adventures, gain a fat purse of coin and live the good life until it runs out.
That gives plenty of time for downtime activities and gives the players time to engage with the world and RP with each other.
D&D is two thirds combat.
For better or worse the system does little to provide mechanics or a framework for the other two tiers of play. As someone who enjoys the outdoors backpacking, canoeing, climbing, and orienteering, it always feels like RPGs are written by people who don’t spend a lot of time outdoors.
Exposure and illness are way more likely to kill a traveler than combat. I want to introduce travel and camping duties. I also have a different way of measuring the toll of travel. I explain the duties in this post: Duty Roster: Camp & Travel
A less tedious way of doing the book keeping of D&D. I don’t want to hand wave it completely.
d10>d8>d6>d4>1>0. It’s useful for tracking
I’ll dive into this topic more in a different blog post.
I’ll dive into the Worldbuilding Abstract with Gods & Religions.