The history of Dungeons and Dragons, especially recent history, is all about the mystical notion of game balance. Fourth Edition was designed the way it was in part to repent for the excesses of Third Edition, and Fifth Edition was designed the way it was in part to repent for the excesses of Fourth. Fifth Edition also comes closest of any edition of D&D (save maybe the very first) to accepting a more broad axiomatic truth: Mechanical game balance doesn’t actually matter.
I mean, it matters in certain situations. The GMing tools in D&D are, at least since Third Edition, designed around the concept that combat can be statistically constrained in ways that make challenge consistent and predictable. As anyone who’s actually used the Challenge Rating system knows, this is of limited use in an actual game. But, there’s a reason that D&D uses these tools, and a reason that very few other games do. While putting forth effort to fine-tune the aspects of combat (and mechanical balance does almost exclusively apply to combat) is fine, good, and useful, it is not a substitute for the sort of balance that will actually make your game run better and keep your players happy.
While your campaign can have one of any number of goals, be them story, exploration, or accumulation of treasure, you have one simple goal in any session you run: make sure your players are having fun. The first step to this is always to make sure that all of your players get a roughly equal chance to contribute. Of course, this is easier said than done, which is exactly why I’m writing a whole article about it. There are two important things to remember: contributions and spotlight. The two often run together, but sometimes must be managed quite separately.
Contribution balancing is the origin, roughly speaking, of mechanical balance schemes like point buy character generation, levels, and challenge ratings. If characters are of an equal power rating, they should in theory have the same ability to sway the outcome of a conflict. D&D does this fairly well, but only for combat. Other games, even those like GURPS with a very finely weighted mathematical value system, only provide a bare framework. And GURPS, being a universal game, is a great example for the problem as a whole: the system is not balanced for your game specifically. If you were to pick up the GURPS Characters book of the Basic Set, you could flip to the skills section and find a vast number of very different skills with very different degrees of usefulness. An interesting decision made by the authors of GURPS was to assign point ratings to the skills based on their complexity and difficulty, not their applicability. This means it costs fewer points to learn how to shoot a gun than it does to learn physics, despite the fact that shooting a gun will be much more useful in most games. And of course, learning the “Guns” skill is useless if you’re playing a sword and sorcery game, but GURPS the system doesn’t know that.
One thing GURPS does fairly well in its GM advice is make it clear that the GM is responsible for drawing a line around what is and isn’t useful or allowed in their campaign. That is something GMs should do in every campaign they run, generic system or not. While some games are tight enough that every mechanic offered should be applicable in the game’s genre purview (most PbtA games are like this), the vast majority offer more options than a typical campaign will use. In D&D, a Ranger or Druid could be sitting on their hands if you decide to run a game that takes place entirely within a city, for instance. This can be resolved one of two ways, depending on how flexible you can be. First, broadcast the campaign concept loud and clear, so players know what character concepts are appropriate. This is also the right time to make sure there isn’t too much overlap: two characters good at the same thing means both of them get less to do overall. Second, if you find a character without much to do in your campaign, add things for them to do. When you prep for sessions, look at every character and make sure there’s at least one moment where they get to shine. Even in the middle of a game it pays to re-evaluate. If your characters found or bought an interesting piece of gear, make it relevant immediately, or at least put in a situation where a player would try to use it (and trust me, the new and shiny thing will get pulled out first). Doing cool stuff is a big part of what makes gaming sessions memorable and fun, so just make sure everyone is doing cool stuff or at least getting the opportunity.
In some ways, spotlight and contribution run on parallel tracks. When a character is using their abilities and doing cool stuff, they tend to be in the spotlight. Where contribution and spotlight diverge, however, is where you need to be careful and do a little more work to ensure that all players are getting their time to shine.
The biggest place where contribution doesn’t necessarily guarantee spotlight is with support characters. Your medics, your drivers, your tech/craft types, these are all characters that may have plenty to do, but won’t necessarily get the recognition or time in the sun in the same way that other characters (especially those talking or fighting) do. Your medics/clerics/doctor types are the classic victim of this. Healing up all the other characters after a fight does *not* count as spotlight time, even if the character is contributing. The D&D mode of acknowledgment that being a heal-bot isn’t all that much fun came from giving clerics other things to do, but it’s a little less direct in other games and almost always requires effort. Apocalypse World does the best job of making being a healer interesting by actually giving healing some mechanics to engage with. The Angel playbook has some great specific things to do as part of a broader arc, and getting hurt is so rough in the game that they end up being more important than a cleric in D&D (who finds their healing abilities replaced by potions or worse, the wizard). I’d say having a dedicated healer may make more sense in grittier games. D&D de-emphasized cleric-as-healer a lot in Fourth and Fifth Edition for that reason. Tech and driver types have it a little better, but it still ends up in the GM’s lap to try and engage them. And you still see systems try to sidestep it. Shadowrun gave Riggers drones in Fourth Edition because driving and vehicles wasn’t enough, and most craft/artificer types have disappeared from games without a dedicated crafting or gadget system.
So if you’re playing a structured game like Apocalypse World or D&D, you’re essentially told if the character type you’re thinking of is supported. Apocalypse World has a driver and a healer and a tech, while D&D for the most part does not. In something more freeform, like Fate or GURPS, it is up to you to make sure that the character not only has something to do, but has something to do that is important and that is engaging. This is actually much easier in a game like Fate, where the mechanics are on very flat ground with regard to any task you could try to do. If you’re using a system which has very lopsided emphasis (like D&D with combat) or disjointed mechanics (like Shadowrun), you may find yourself working uphill a bit. This is where talking to your players helps. If you’re able to understand what they envision their character doing and what they think is cool about their perception of their character, you will be better able to direct your efforts towards making this vision come true. Even better is if you understand how this meshes in with the party, because at the end of the day you’re balancing the time between everyone playing.
If you aren’t sure you can get the mechanical spotlight quite right, make up for it with plot spotlight. Raid those backstories and dangle MacGuffins. If you’ve had a string of combat-heavy nights where your Street Samurai and Adept are kicking ass, mix it up with the Rigger and their shop. Spotlight is about making players feel important, and not necessarily about engaging with the mechanics all the time. Remember player motivations, too. Some players will be way more thrilled about having time to investigate their family’s dark past than they will be with trying to figure out how to write a technomancer. And if you can’t figure out a way to get every player to the forefront one night, that’s OK. But remember who was in the background so you can give them some love next time.
When it comes to game balance that matters, it’s all about making sure players are contributing equally and all have interesting things to do. This means that it’s perfectly OK to leave the mechanical balancing act at the door if you can still have a game where everyone gets to be important. Apocalypse World brings disparate characters together in a way D&D simply couldn’t . . . after all, how do you balance the guy with a workshop who makes gadgets with the guy who has his own motorcycle gang with the guy who has his own death cult? Even if the characters would be awfully mismatched in a fight, they still can all contribute to the story at the same level, which is ultimately what’s important.