Is it at all possible to create/homebrew a class with half-subclasses?

Question

Sonny is a great little game starring a zombie who starts out with limited skills (a super-basic attack and a self-healing spell) and gains more skills as he levels up. At two points in the game, you get access to an additional skill tree (you can choose between five or so each time). Other than having more time to level up the skills from your first chosen tree (which is rendered moot by being able to respec at any point anyway), given two choices, the order in which you pick them has no bearing on what you can do once you’ve picked both.

I’m wondering whether this can be brought to 5e or it’s just too different from how 5e works to be compatible.

I’m thinking a class could have five or six half-subclasses and the PC would be able to select one at level 3 and one at level 12 or so. Is this at all possible without leaving the PC with two weaker choices (in D&D, the features they gain from level 12 to level 20 should be stronger than those they gain from level 3 to level 11, but here, since both options would be available at level 3, they must be equally strong, which makes the class either overpowered at low levels or underpowered at high levels)?

Example of sorts: Warlocks have something similar because they have both pacts and patrons, each of which constitutes a half-subclass in the sense that the warlock must pick one of each. What I want to do is more or less equivalent to what the warlock would be like if patrons were also called pacts and the warlock had to pick two pacts at different levels (then we could have a GOO/Archfey warlock, a GOO/chain warlock or a chain/tome warlock).

To clarify: I’d like to know if people think it can be done without sacrificing balance, since at the moment, to me, it seems like the class would be either too strong at low levels or too weak at high levels.

Answer 1

With enough effort, yes, absolutely.

The real key here will be making most of the abilities scale base on your level. For example, bardic inspiration or maneuver masters die size, and monks unarmed strike damage all scale base on the level of the character in that class. The other option is to have the sub-classes grant bonuses based on what other subclass you opt into. Lets say everything is elemental themed, and the options are fire, ice, wind, earth, and water. The first option they go for is fire, and maybe it gives them a small damage buff on their attacks. Then the next decision point comes along, and they pick ice.

If you went with the "everything scales based on class level" they gain the ice effect, and it's immediately raised to the level 12 tier of strength, along with the fire effect becoming the level 12 tier. You're also going to have to remember with this route, each of the level 12 tier of abilities they gain are going to necessarily be about half the strength of a comparable feature from another class, since they'll have 2x as many features.

If you opted for the "things combo" route, instead of gaining the ice abilities, the fire abilities are replaced with some sort of "combo ability" that is themed after a mix of the two effects that they picked. This will also somewhat alleviate the necessary weakness of the low level abilities since they get replaced entirely. You could also opt to allow them to pick the same category twice and to just power up the abilities of that category rather than replace them entirely.

Answer 2

Maybe, but it would require a fundamental redesign of subclasses, or design of a new feature, to work

Allowing a PC to take two options at once would present balance difficulties, as you have already surmised. You could build new features to enable such a system, since the Warlock does give some bit of a precedent of how that'd work.

Consider the Warlock pacts. While the Patron gives features at several class levels, the Pact only gives a feature at third level. Anything else relating to the choice of Pact simply uses it as a pre-requisite, mainly Invocations.

To incorporate a similar, "half-subclass" as you put it, into the other player classes would require design of a brand new feature, similar in terms of added functionality to the Warlock Pacts. Simply giving access to a second entire subclass or even select features from it would unbalance the system if not compensated for elsewhere.

An off-the-top-of-my-head example would be something like allowing a bard to specialize in a specific instrument, providing a minor added effect to spells that are cast with that instrument as a focus.