Using Hit Dice as a Feature Resource

Dungeons & Dragons, like many RPGs, is a game heavily centered around resource management. Whether you’re tracking spell slots, maneuver dice, or ammunition, the ability to make meaningful decisions based on limited resources lies at the heart of the gameplay. In D&D 5th Edition, the most significant resource is, of course, your hit points. But beyond that, you’re managing an array of resources specific to your class and subclass. For example, Wizards track their spell slots, while Fighters manage their use of Second Wind, Action Surge, etc.

Each feature presents you with a meaningful choice: given it’s availability, when should you use the feature? For instance, the Fighter’s Action Surge can be used just once per rest, so you must think carefully about the best time to use this powerful option.

Proficiency Bonus as a Resource Mechanism

An idea introduced more recently, possibly in Tasha’s Cauldron of Everything, is to use proficiency bonus as a measure of how many times a feature can be used. An example of this is the Barbarian’s Infectious Fury, which resets all expended uses on a long rest. This pattern of resource tracking offers tactical flexibility, letting you either front-load your feature uses early in the session, space them out evenly, or save them for crucial moments near the session's climax. However, there are two issues:

1. Bookkeeping Overload: Another resource to track adds to an already considerable list, potentially overwhelming players who dislike "bookkeeping."

2. Abstract Nature: Using proficiency bonus is somewhat abstract and "gamey." It can feel arbitrary and lacks a strong in-world explanation.

Hit Dice as a Feature Resource

One emerging idea from third-party designers is to use hit dice as a resource for class features. Hit dice are traditionally only used during short rests to recover hit points. However, Ghostfire Gaming’s Blood Druid also uses hit dice as a currency to power some abilities.

This approach offers two primary advantages:

1. Reduced Bookkeeping: You’re already tracking hit dice from level 1, so using them for features doesn’t add any additional numbers to manage.

2. Game Fiction Alignment: Hit dice represent a character’s stamina and recoverability, making them feel more grounded and less arbitrary. Spending a hit die to pull off a remarkable feat aligns with the idea of a character pushing their limits to achieve something extraordinary.

Challenges and Downsides

While using hit dice as a feature resource is clean and immersive, there are a couple of downsides:

1. Healing Resource Trade-off: Spending hit dice on features means fewer hit dice available for healing during short rests, which could lead to tougher decisions during prolonged exploration.

2. Scaling Complexity: Higher-level characters have a lot more hit dice. By level 20, a character can have up to 20 hit dice but only a proficiency bonus of +6, whereas a level 1 character has 1 hit die but a proficiency bonus of +2. This means that features tied to hit dice become dis-proportionally more plentiful at higher levels.

To balance these negatives, features should be powerful enough to justify spending hit dice. At lower levels, it may seem costly, but by mid-level, the investment should feel worthwhile. Moreover, features tied to other tracking methods can still complement those using hit dice. You could have a mix of features, including those that are always available, as well as those that reset on both short and long rests.

Final Thoughts

I believe incorporating hit dice as a feature resource can add meaningful depth to subclass design. I’m considering it in my own designs, finding it a clean and immersive way to handle powerful features without overwhelming players with extra bookkeeping.

Would I convert all subclasses to this system? Probably not. It's crucial to maintain balance, particularly at lower levels where spending hit dice can be more punishing. Nonetheless, I’m curious why Wizards of the Coast hasn't explored this concept further. It seems like a natural step to take that generally aligns with 5e’s design philosophy.