I recently saw a post on Reddit describing some home-brew rules for gestalt characters in 5e. It seemed interesting so I looked up the original 3.5e gestalt character rules (which can be found here for anyone that's interested: http://www.d20srd.org/srd/variant/classes/gestaltCharacters.htm)
There are several rule variants in the 5e DMG that can allow for more powerful characters already; shorter rest variants, high-magic campaigns, etc. so I think new 5e rules for gestalt characters is certainly one that is possible, especially when you consider that the action economy will still provide a limit on what these characters can do (in combat at least).
As the current rules don't include gestalt characters, house-rules would need to be used for this to work, so my question is:
How close can you get to creating a 5e gestalt character using the old 3.5e rules and is there anything that would need to be done differently in 5e?
Some things (i.e. spell casting) could easily be handled like they would with a multi-classed character but other things don't seem to quite fit. Would each classes' ability score increases or first level proficiencies need to be handled differently, for example, to prevent game-breaking imbalances?