What does power cost the players in your game?
Consider the druid and their emblematic wild shape ability. D&D 5E players shift between forms with the gleeful ease of Beast Boy from Teen Titans. The D&D “Honor Among Thieves” movie includes a scene where the druid rapidly shifts from form to form in the same manner, and this scene, like much of the movie, is very much shot using superhero logic, not sword and sorcery logic.
That’s all well and good for a game that wants a superheroic tone. But what if we want a darker or more weighty feel? Consider the following:
As a boy, Ogion like all boys had thought it would be a very pleasant game to take by art-magic whatever shape one liked, man or beast, tree or cloud, and so to play at a thousand beings. But as a wizard he had learned the price of the game, which is the peril of losing one’s self, playing away the truth. The longer a man stays in a form not his own, the greater this peril. Every prentice-sorcerer learns the tale of the wizard Bordger of Way, who delighted in taking bear’s shape, and did so more and more often until the bear grew in him and the man died away, and he became a bear, and killed his own little son in the forests, and was hunted down and slain. And no one knows how many of the dolphins that leap in the waters of the Inmost Sea were men once, wise men, who forgot their wisdom and their name in the joy of the restless sea.
-“A Wizard of Earthsea,” Ursula Le Guin
Incorporating this idea immediately changes how wild shape feels as a druid ability. Can we build power-with-a-cost into each of the 12 classes in 2014 5E? Let’s find out. This is a concept only, and definitely does not attempt to balance these costs against each other.
Druid. The Earthsea example above guides the way; it’s just a question of which criteria informs the cost. How long the character stays in animal form is an easy one. But it could also weigh how often the PC assumes the same form. That could disincentivize just falling back on the same few animal forms over and over again. Another type of cost would be to scale it against the power or unusual nature of the animal in question. Transforming into a dog is relatively safe; transforming into a tyrannosaurus rex seriously risks the druid’s ability to hold onto their humanity.
Warlock. This is the easiest to do given how naturally the fiction of the patron implies that being a warlock should mean power-at-a-cost. The rules don’t really support it mechanically, but I believe many 5E games have informally steered into this aspect of the warlock. Critical Role’s second season delivers on this fiction, without any explicit mechanical hook obligating the players to do so. A patron could grant and retract powers in relation to how much the PC is fulfilling the patron’s desires. It could even be the basis for milestone leveling in the right game.
Sorcerer. This one also emerges organically from the fiction. A character’s bloodline provides their power, but they do not master magic the way a wizard does; they are riding the tiger. Simply allow sorcerers to go into the red on sorcery points, and bake in some risk of their powers going haywire. It’s easiest to visualize for wild magic sorcerers; the wild magic table provides plenty of room for a cockup cascade. But it’s not too difficult to come up with consequences for the other bloodlines as well.
Wizard. Wizards seek spells through study and knowledge, but the modern game has gradually given them more and more control over their spell selection, such that finding a scroll in a modern game is not nearly as exciting as in an old-school campaign. In a game that much more strongly incentivizes wizards to learn spells diegetically, it is much easier to provide a cost. Transcribing a spell to the spellbook carries risk, and not just the risk that transcription will fail. Will it take longer to transcribe?Will it be an unreliable variant of the spell? Or could it be something worse? Is the spell like a living thing, a malevolent entity now making its home in your spellbook?
Bard. Relative to the other full-casting classes, the bard’s spellcasting seems to come with the least implied risk, labor, and commitment, so let’s not focus on their spells. Instead, consider bardic inspiration. It’s interesting that in 5E’s oops-all-magic approach to character abilities, bardic inspiration is actually a non-magical effect, which implies a world where mundane motivation can propel people to greatly improved performance. Bards could themselves endure wild swings from excessive exuberance to sinking depression that mirrors the swingy outcomes their inspiring words produce.
Rogue. The costs for the rogue are the most obvious in some ways, but also the hardest to implement due to modern play’s promise that players are free from many kinds of social restraint. Some kind of reputation or "heat" mechanic would serve as a natural cost for a rogue. Ideally it would create risk in the same places where many of the rogue’s abilities shine, i.e., cities and other bastions of civilization.
Cleric. Modern D&D has gradually shed many of the restrictions that once characterized classes like clerics. Simply bringing back some of those limitations would produce a cost that would go along with their power. Use Knave 2’s relic system for inspiration.
Paladin. The paladin is like the cleric, but their complication is less of a personal relationship with a particular divinity. Instead, they are defined by oaths and quests – socially mediated principles, whether as shared aspects of chivalry with other paladins, or a more personal code. D&D 5E’s oaths are all upside, a collection of archetypal powers; but they do include tenets that imply restrictions or downsides that would limit the paladin’s power or constrain their actions in interesting ways.
Barbarian. This is another class that once featured more costs and restrictions, but they too often constrained the player’s choices rather than presenting interesting drawbacks. A barbarian who blindly attacks allies in a frenzy -- or abhors magical items -- fits the fiction, but it doesn’t make for interesting play. Instead consider a barbarian who must decide, when they initiate a rage, how long they will rage; and rule that they can't retreat until it is over, even if they overestimated the length of the fight.
Fighter. As the “most straightforward” martial class, it is difficult to apply costs to fighter. The second wind and action surge abilities suggest endurance, so allow the fighters to tap into those resources more aggressively, with exhaustion as a consequence. This kinda steps on the toes of the berserker barbarian… but I’ve never actually had a player choose the berserker barbarian, so that would be a theoretical problem more than an actual one for me.
Monk. This one is also challenging. To separate the monks from the fighters, we can imagine monks overclocking not on actions or HP, but on defense and maneuverability. Consider tying costs to more extreme usages of slow fall or evasion abilities, or even lean into the diamond soul ability by allowing them to spend ki points to pass otherwise-failed saves, with a penalty to future saves proportional to how emptied-out their chi pool is.
Ranger. The hardest of all? A ranger could lose their civilized self, but it’s hard to imagine it as severe as the druid’s transformation. If we presume that many rangers are loners whose mastery of the wilderness came in relative isolation, we could make their ability to navigate and survive progressively harder the more people they are trying to guide or protect.