So I had this idea in the shower, where I get some of my craziest conceptions.

Suppose I only have three players and I want to run a campaign with more characters for various reasons BUT I want to avoid the dangers of DMPCs....

How about you have each player roll 2 characters.  The first, their primary, rolled by standard 5e rules of your choic,e and a secondy, character rolled by HARD CORE* rules.  The player would be told devise a relationship between the two characters.  (I/e master/servant, intimate partners, school chums, fellow veterans, siblings or cousins, etch...)

Then:  HAVE THE PLAYERS PASS THEIR SECONDARY CHARACTER TO THE PLAYER ON THEIR RIGHT FOR PLAY(or left, or whatever)

Now you have six characters to fill out party needs but you have a mechanism to ameliorate self serving players sacrificing one of their pair to the needs of the other. 

And LOTS of opportunity for intra-party roll play.

Thoughts?  Comments?

* HARDCORE or OLD SCHOOL rules:  Roll three dice instead of 4 and record them on the character sheet in the order as rolled.  Also roll 1st level hit points.  (maybe let them re-roll 1s or 2s?) Creates a fragile and challenging character to play in 5e.  This is intended to create a dynamic tension within the party because of the players responsible for playing them is answerable to the players who created them.

I’m not sure I understand the purpose of the second character using the “hardcore” creation rules.

Aside from that, though, it sounds really interesting. This is just personal preference and comfort, but six PCs is too many for me, regardless of number of players. Three is actually my ideal party size. So I wouldn’t try something like this to turn three players into six characters. But turning two players into four characters? That’s where it could be really interesting.

Developing the relationship and then handing off the character to another player seems really interesting.

Oh heck yeah. Back when my brother and I were kids we played games with just two of us, he’d run three characters and I’d run two plus the monsters. It was a lot of fun! Plus, I’ve played games with the “pass to the right” mechanic like Ten Candles, and it’s one of the coolest things I’ve seen. So yeah, great idea! Although depending on the group I’d consider using the new sidekick rules instead of hardcore mode, because they’re simpler and still less powerful.

The only game I recall us playing up through college with only 1 PC per player was Champions.

We always played 2 or more PCs per player in D&D because we never had enough people for a large party. Most of the time there were 4 of us, 1 DM + 3 players, so we would play with 2 characters per player.

If you want to add the gimmick of a hardcore rolled character for one of them I don't see the problem with it, but I also don't see any particular need to do that either.

It's your game. I wouldn't want to give inexperienced players multiple characters though. I would want new players to learn how to play and feel out how their characters work rather then have any confusion between difference races and classes.

However, if your players are up to it, go ahead. You might also consider 3 mains and 3 henchmen or followers. 

Why the hardcore and not just a henchman? One word:  Drama.  Drama is created by jeopardy.  Jeopardy only comes when something of value is at risk.  I want the secondary to be challenging to play (thus providing risk) but still a fully realized character (thus having value) running on the same rules and the same potential for growth as all the other characters. 

This is interesting...I definitely don't see an issue with players coming up with multiple PCs, or at least a primary PC and one or two followers, sidekicks, etc... what makes me wary about this idea is the pass the PC to someone else for them to play, and I'm seeing this from a group dynamics point of view rather than mechanics. 

Obviously I don't know anything about your group dynamics, so this is just my gut reaction. I am very wary of the idea of someone making a character and then dropping it in someone else's lap and saying you have to play this. I could easily see something like one player coming up with a character that they find very interesting, but the person who its passed to could feel completely differently.

Maybe its a male player being given a female PC and feeling a bit out of their depth with RP, maybe one player wants to explore the dynamics of being a half-elf against an elf PC who comes from a xenophobic community but the other player isn't comfortable playing a more xenophobic PC, perhaps the player just finds the PC they've been given as boring and kinda doesn't put a lot of effort into the RP which lessens the enjoyment for the player who made that PC, or maybe the player was just really looking forward to playing a barbarian and now they have to run a wizard too.

I am not saying that is can't work, but I think it would probably be difficult to pull off. If you're considering doing this I think it would require A LOT of group discussions, and total buy in from everyone at the table. Maybe it would be great and allow for really dynamic RP, but I can also see a bunch of ways this goes wrong.