Possible issues of a player switching Bard archetypes randomly with long rests?

Question

One of my players want to play a Bard with multiple-personalities. At every long-rest, the idea is that he randomly wakes up with one of his personalities. Each personality is very different from the other and each inherits a different Bard archetype. So, with every long rest, he uses a different char sheet. We would start with 2 personalities at level 3 (Lore and Glamour) and then work from there, possibly increasing if adequate. Our idea was to only change a few things between each sheet:

• Spell list
• Personality and Traits
• Subclass features

What are possible issues of doing this? Are there any red flags to look-out for regarding possible exploits?

Answer 1

Mechanical complexity

Even playing a normal caster, the mechanical complexity of the spell library is not trivial to manage. With the subclass swapping, one'd effectively be doubling the difficulties of managing the most complex part of the character. The player'll also need to keep track of two different sets of College features (possibly more). I forecast human errors stemming from this increased mechanical burden to memorize.

Since you ask regarding exploits: the GM has a hard enough time remembering who knows which spell and has which power in normal gameplay. With this subclass switching deal, the player in question can slip in (accidentally or otherwise) features or spells that are exclusive to the wrong subclass. A GM can be alert about it, but it's definitely cognitively taxing for them as well. The swapping can also make content planning more difficult, as one can't rely on the character on eg. having a spell they took for just one of their personalities, or being capable in melee because they might wake up being a Lore Bard instead of a Valor Bard.

Having to level up two separate "branches" of the same character is another issue. If you do level-ups around the table, this can result in the Bard player being slower than the others.

Overall, this gimmick sounds to me like it's a fair amount of work for a small bit of novelty value. I would be very apprehensive about implementing this in actual gameplay.

Answer 2

No exploits, but many disadvantages

As long as it is really random each morning, there is not much to exploit.

Even if he picks one each morning, it is just a tiny bit stronger than a usual bard.

Downsides

The bookkeeping alone would discourage me.

The inventory management is even worse, only some bards can use medium armor and shields. So you will have to lug around two sets of armor, maybe even different kinds of weapons.
Each prefers different equipment and play style.

Answer 3

The other answers point out the mechanical burden well, so here are a few other considerations.

Roleplaying Consequences

Regardless of when the personalities manifest, and what the player and the DM have to keep track of, there is also the party and flow of play to consider. Do all the personalities have the same alignment? Do they have access to the same memories? It could be jarring for the party to have a game plan going in to a long rest, only to find one of their members does not remember the plan, or worse just doesn't agree with it. This could add a lot of drag to group decision making.

Another big wrench in the whole thing, waking up with a different personality everyday is an unlikely manifestation of Dissociative Identity Disorder. The character would likely change personalities due to stress or other environmental triggers (which would make it even harder to play). Waking up with a different personality feels arbitrary, and probably is due to the fact that mechanically it's the only way to keep the access to spells and subclass features from being completely broken.

Intent

Assuming the best case scenario that the personalities have access to the same information, generally have the same values and opinions, and neatly wake up everyday with different abilities... why do they want to do it? Great characters are best built around a core personality where the abilities and stats are an expression of that personality. Trying to hack around the limitations of the rules, or avoid making a clear decision about what your character is (or is not) is going to lead to confusing and difficult roleplaying (if it's possible to roleplay at all). Maybe roleplay isn't a big concern for your player or the group, but in that case simple is better, and this character is not simple by any means!

In the end, you want your player to enjoy their character, but they might be happier with multi-classing if they are not ready to be decisive.