One of my players has requested that his next PC actually be two characters, similar to "Ferra & Tor" from Mortal Kombat, essentially a small wizard (or other magic user) riding a big barbarian (or other "tank" charactor). He proposes that in order to not seem OP “Every time I get hit, roll a d10 + strength modifier and if it rolls higher than a 7 or 8 I get separated” and if they get separated he has disadvantage on everything and reduced senses and stats.
His exact request was:
My character is actually two characters; one big tanky guy with a smaller, weak spellcaster sitting on his head/shoulders. Together, they're pretty powerful being able to tank and spellcast, but if they get separated from each other, then I get disadvantage on everything and reduced senses and stats
And I'd only be able to attack once with maybe a bonus action to be able to cast a simple spell. To balance it, I was thinking about having a level 4 tank and a level 2 wizard or something in the one character, trying not to make him OP"
This to me sound like a careful balancing act between being too OP or too UP, depending on what he has to roll in order to "become separated".
With the rest of a party on Level 5, Can anyone tell me how to balance this character? Such as…
- What disadvantage it should get when separated?
- How to make initiative work if they separate or join up mid battle?
- How the separation mechanic should work including what dice and modifiers?
And any other advice on how to make this character function without bending the rules too much.
Best Answer
Just use a regular multiclass character treated narratively as two characters.
I've tried the same thing you're describing (two characters in one) at my table before as a party-controlled NPC companion. I tried several iterations of homebrew, but all suffered from balance issues and caused confusion during play.
Eventually I tried the character as a by-the-book multiclass character treated only narratively as if it were two characters. This worked the best at my table in terms of balance and playability.
With a simple multiclass character, the player can have access to barbarian and wizard features, and in dialog and roleplay they can pretend the two are separate, but mechanically there are no special rules to contend with for the players or you as the DM. The two can be treated as psychically or spiritually linked so that it makes sense that they share one stat block. I suggest ignoring the minimum ability score restrictions for multiclassing with this character, since barbarian and wizard will be difficult to assign scores for competently.
Perhaps this counts as a frame challenge (rejecting the kind of answer you're asking for in favor of an alternative solution), but I've been there and done that with the kind of homebrew you're describing and it did not work out well in my experience, so I'm trying to save you the headache.