gestalt

An organized whole that is perceived as more than the sum of its parts. Anyone that is familar with d&d 3.5 might know about a rule varraint call "gestalt" a high-powered campaign variant, characters essentially take two classes at every level, choosing the best aspects of each. with any over lapping features taking the best from the best of the two such as hit dice, attack progression and, saves.

why gestalt?

Gestalt campaigns are high-power campaigns that don't rely on magic items or levels. A party of 2 in a gestalt campaign is the equivlaint of a paty of 3 or 4 and thus allow a smaller group to have all the roles they need in an adventure. So you can run a module meant for a party of 4 with only two or three people.

basics

If you have never read the gestalt rules stop right here and read the rules here it will save you a lot of headache going forward but, I will give you some of the key points.

Characters: Chracters in a gestalt campaign are writen as class//class or class|class inorder to keep the two lines sperate.

Classes: You are not allowed to have two of the same class on oppisite sides. No Wizard//Wizard or Fighter//Fighter

Balance: Its impossible to keep gestalt campaigns inline with normal modules. Example: a Fighter 5//Sorcerer 5 is going to cast a twinned linked haste on itself then action surge for two attacks and attack twice with its haste then bonus action quicken a green-flame blade. Next turn take the attack action to hit twice, use the two haste action to hit two more times. Two turns 9 attacks at the cost of 3rd level slot, 5 sorcerer points, and an action surge. You need to keep that in mind whenever running a gestalt campaign.

Limiting: Some classes, class combos or, subclasses you might need to ban because they are too appleaing as choices. If a Fighter/Warlock is good a Fighter//Warlock is great.

the warlock problem The warlock is a great choice for any class. A Fighter//Warlock will enjoy being a short rest master with a host of spells, invocation, (if you are allowing ua's) smiting for 10d8 with every attack. A Sorcerer//Warlock will enjoy the extra free spells from invocations that can be used with metamagic, the short rest slots, the ability to use the sorcerer slots with the lower level warlock spells and, the ability to cast eldritch blast as a bonus action (a normal Sorcerer/Warlock can do this too but, its a good side note that the sorcerer has to lose in order to gain this where here it does not). The Bard//Warlock gets most of the same befits as the Sorcerer plus the Lore Bard and Pact of the Tome can really diverify its spell casting toolbelt to even rival the wizard. But I thnk you get my point Warlock is something that is extremely appealing to take with any class and something you might want to outright ban from play. Some players might be angry saying that it is their favorite class but, trust me you will have powerful enough characters without it.

Other things to keep in mind

Gestalt campaigns are meant for a few players if you have a four man team you don't need to run a gestalt campaign you have all you need right there. There is no need to gestalt as all the typical rolls can be filled. (Support/healing, face, damage, frontline) so here is some things you might want to have in the back of you mind when playing.

Action Economy: The Fighter//Sorcerer has over came the action economy with a use of spells and its action surge. A costly two turns that they might be saved for a final boss or a hard encounted of some kind but, the players are still limited by the one action, one bouns action, one reaction rule. So while a fighter//cleric can attack and heal, they still must follow the rules of the game.

Magic Items: With all that a player can do with their turn giving them a magic item that needs an action or bonus action to use is going to be sold or ignored. They already have a huge toolbelt that can be accessed using all their actions.

Homebrews: there are a lot of good homebrews out there. Subclasses, full classes, races, you name it. I wouldn't allow any of them. even if they are balanced. There is a fine line here that needs to be kept in place because one step can lead to a super powerful character. Just keep it vanilla.