I was filling out the D&D Classes Survey from Wizards of the Coat the other day. It is clearly aimed at looking at play experience, since it asks you which classes and subclasses you have played before unlocking the opinion questions about them. One of the things I noticed from my own experience, was that, while I have played a wide number of classes: 1) I have favorite subclasses and not as much experience outside of them, and: 2) I couldn’t offer an opinion on many of the high-level class abilities, because the characters I played never made it to those levels. I have played a lot of D&D, but few, if any, of my campaigns have made it up past 15th level. Many more haven’t even made it past 10th.
That led me to think that it’s unfortunate that many campaigns deny players a chance to experience what are supposed to be the pinnacles of their characters’ potential, which led me to consider the following option:
You have access to one use of a higher-level feature of your class. If this feature is ordinarily permanent or long-lasting, it lasts for a minute once it is invoked. If the feature affects or is performed in a single action or round, then it lasts for only that use. The class feature operates at the level of ability you currently possess or its minimum operational level, if your current level is insufficient, and uses traits (ability scores, bonuses, save DCs, etc.) you currently possess.
So, for examples, a lower-level barbarian might gain one use of a brutal critical or one instance of indomitable might, a fighter might gain an indomitable saving throw or use of a maneuver they don’t normally possess (perhaps even with an increased Superiority Die), a lower-level paladin might gain a minute of aura of courage, a Circle of the Moon druid one use of elemental wild shape, or a spellcaster one use of a spell higher level than they can normally cast (using their highest level spell slot to cast it).
The Cost of a Power Surge
At the end of an encounter where a character performs a power surge, that character gains 1 level of exhaustion, reflecting the strain they have exerted in extending their abilities. At the DM’s discretion, higher level power surges (or ones with a larger difference from the character’s current level) may impose multiple levels of exhaustion, although rarely more than 3.
If you want a harder power surge cost, the resulting exhaustion is half the difference between the character’s current level and the level of the power surge feature, rounded down, which effectively limits a power surge to an 11-level difference (5 levels of exhaustion) since 6 levels would kill the character (although it would be quite a way to go!).
Acquiring a Power Surge
Characters acquire the ability to perform a power surge as a boon granted by the DM, similar in some regards to a charm (see Supernatural Gifts in the Dungeon Master’s Guide). This may come from an in-game agency like a deity, powerful creature, wise mentor, spirit guide, or the like, or simply occur as a story-related event, much like Inspiration. Indeed, a power surge can be thought of as an “advanced” use of Inspiration for giving a particular character a “spotlight moment.”
When a surge is granted, the DM specifies what class feature it grants, or may offer a choice of class features; the surge is not good for whatever higher-level feature the player wants! The feature may be negotiable, based on player input, but the DM has the final say in the matter, taking campaign considerations into account (see Power Surge Considerations, following).
Power Surge Considerations
Naturally, power surges are things the Dungeon Master should permit carefully and sparingly, with an eye towards not disrupting the flow of the game too much. Some higher-level class features may be too powerful as power surges, depending on the current level of the character and the overall conditions of the campaign and adventure.
At least, a power surge should be a rare event, something that doesn’t happen more than once per character level (at most) and probably less often than that. It shouldn’t necessarily be something players can plan around or expect, but that shows up at moments of dramatic importance in the campaign. It’s also an opportunity the DM should spread out amongst the player characters—with no one character getting two or more power surges in a row before the other characters in the party have gotten an opportunity.
The availability of a power surge may require some adjustment to the challenge level of certain encounters, but then a power surge is supposed to be impressive, so it is all right if it happens to make a difficult encounter easier than it would otherwise be. Just be prepared to adjust things behind the scenes if necessary, should a power surge come off as anticlimatic rather than an epic peak or finish to an encounter.