“You can play however you want and be whoever you want”
That’s how roleplaying games were once described to me. And to an extend that’s true. With the right GM you can play any sort of setting, from Game of Thrones with the serial numbers filed off to a setting where you can fly through space on the back of dragons shooting lasers at storm troopers.
And as a part of that, the players will work together to make create a world, intricate lore and compelling characters. However, what most people will do is use a standard set of rules and everything that comes with it. And that often results in a game that has an amazing backstory and awesome lore but whose mechanics have no way of representing that awesome lore.
Often, I’ve heard this problem described as “Playing Game of Thrones in D&D and being surprised there’s no feats for ruling nations”, which is a much more exaggerated version of this issue. I’m not going to be talking here about choosing an entirely wrong system for your game (But please, consider the system before you play). What I will be talking about is creating rules adjustments and custom content to make the mechanics of the game reflect the reality of the game’s universe.
The easiest kind of adjustment of this category is removing things that don’t fit in your world. Don’t have martial orders of devout defenders of the faith in your game? Remove paladins. Don’t have direct energy weapons in your sci-fi game? Get rid of blasters and lasers. Don’t want your characters to be able to play a noble? Remove that from your game.
You have to be careful doing this though and make sure you don’t remove something that’s vital to the game’s functioning. Removing one of the 13 or so classes is probably not going to impact your game of D&D very much. Removing an entire class of weapons might be a bigger problem, depending on how many alternatives there are. If every weapon in the game is a direct energy weapon, then removing those is going to be an issue if the PCs want to shoot someone. Similarly, the nature of the game will determine if removing the ability to play a noble is a good idea. If you’re playing low-born adventurers, you probably won’t lose anything. But if you’re playing, for example, a courtly intrigue game, you’re taking away a lot of important options.
The second options is tweaking things. Not rewriting rules or adding options but gently tweaking the way the game works to get the result you want for your game. the most common way I end up tweaking games in this way is messing with experience (XP, Levels, Karma, whatever your game calls it) and how it’s gained.
Maybe I want a higher powered game for this particular campaign. One solution would be to increase the amount of xp earned by 50% to make advancement a little faster.
Quick aside: why not just start the PC’s at a higher level? In most games, the player’s learning curve follows the character’s learning curve. As the player gains familiarity with the system, their character learns more and interesting abilities and the player learns to handle them. Traditionally, wizards and clerics in D&D suffer the most from higher level starts. (try figuring out what spells to memorize from a list of literally hundreds) This method allows for a more gradual learning curve.
Or perhaps I want to encourage a specific behavior in my players. Tweaking XP rewards is a good way to handle this as well. Maybe your game has a heavy emphasis on alignment and you want to encourage this in your players. Adding a small XP reward to playing your character’s alignment well is a good way to encourage that behavior. Do make sure you increase the reward as the PCs increase in level so it remains relevant.
Alternatively, you can take away experience for the PCs doing things you don’t like. I personally like removing any ‘show up’ rewards. White wolf games often feature these, just some experience for being present at a session, regardless of whether you did anything.
Another point you can fairly easily tweak is the lethality of the setting. Perhaps you want your setting to be grittier and deadlier. Increase weapon damage or decrease HP by a set factor (10%? 20%) and watch the results. Or maybe you want your PCs to be BIG DAMN HEROES. Give them maximum HP each level (if rolled HP is a thing) or maybe just decrease weapon damage done by enemies.
These small changes can have an enormous impact on your setting and can really make it feel the way you want it to feel.
Last but certainly not least is adding new material. I am a huge fan of this, and unless I am running a premade setting, I will often create new or tweaked races, classes and abilities to represent the things that exist in the world. These sorts of things, whether it’s changing up a few stats or crafting entirely new abilities and races, give your world such a unique flavor that years down the line people will still remember them.
The only thing that you need to be wary of is making new abilities that are strictly better than the previous ones (unless that’s exactly the point)
As an example, for my mega dungeon campaign, I’ve introduced a new class of evil outsider, the Nameless. These creatures are closer to Cthulhu-style beings or Warhammer 40K Daemons than the traditional demons and devils and so i figured that they would warrant their own set of abilities. They’re beings that thrive on pain and hate and wish to invade the mortal plane to turn it into a nightmare version of what it currently is.
Orcs and goblins in my world worship these beings and so they got a set of abilities to match that faith. Instead of the traditional sneaky abilities that goblins tend to have, they can inflict pain on themselves in order to increase their toughness.
In game mechanics, their nimble escape ability is replaced with an ability to draw strength from pain.
Similarly, one of my players had chosen to have the Fiend patron for their warlock. However they were interested in the Nameless Ones so I provided them with a custom Patron to use. They’re happy because they got a cool ability and my game’s world is just that little bit more alive.