Zardnaar
Legend
This will look at multiclassing in 5E and I will provide several examples of some MC builds I have seen in play and discuss a few that are more theory crafting. Some MC builds are pure powergaming, others are to enable concepts the PHB tried to do but arguably failed at such as an arcane gish. The Valor Bard, Bladelock and Eldritch Knight are a bit underwhelming IMHO and MCing can fix them. Best gish is Paladin gish.
In general the advantages of MCing are a dip for some low level class features or taking a more even spread to minimise missing out on ASI's. The drawback of a dip MC build is that you are 1 level behind things like ASI, a spellcaster level or getting a major class feature such as second attack. In general good levels to MC at are level 2,5,7 (as fighter), and 9. Sometimes missing out on an ASI/feat is fine as long as whatever you are gaining is better than a lost feat/ASI. In general classes that are martial based MC well together (eg Fighter, Ranger, Rogue) and even levels and/ore every 3 level are good for 1/3rd and 1/2 spellcasters such as Rangers, Paladins, Eldritch Knights and Arcane Tricksters. For example if you took 6 levels of fighter as an eldritch Knight and wanted to MC into a wizard that is a great cut off point as you pick up an ASI at level 6 and it counts as 2 levels of wizard for the MC spellcaster table. Level 12 would also be another decent MC point for an Eldritch Knight into wizard as you acquire your 3rd attack (your 4th attack may as well be the moon). Giving up a 3rd attack as an MC fighter can be worth it as long as you are happy with the trade off of what you are MCing into. OMe higher level fighter, Ranger and Rogue abilities are often underwhelming so MCIng can be a very good option of them such a a Rogue 8 taking the next 5 levels of Ranger or fighter. You're not giving up much and 5 levels of hunter ranger for example can offer a lot to a Rogue such as a combat type, hunters quarry spell, and possibly 3 attacks a round (2 at ranger 5+ hordebreaker) which triples your chances of a sneak attack. You end up dealing more damage than gaining an extra 3d6 sneak attack.
Another reason to MC is to get better saving throws. Some saves in the game are not very good for example a wizard and Rogue saves are sub par IMHO. Picking up con saves can be worth a dip as well for spellcasters. Due to things such as universal proficiency modifier, ability to cast in armor you can often build an unusual MC character (or single class character) that is surprisingly good in a role you would not typically associate with it such as the Mountain Dwarf Sorcerer beatstick. The Sorlock is probably the best known example of such a build and I will look at that one below. The fighter/mage/cleric/rogue thing is a D&D staple I look at it more as warrior/artillery/support/skirmisher what classes they are matters less.
In general the advantages of MCing are a dip for some low level class features or taking a more even spread to minimise missing out on ASI's. The drawback of a dip MC build is that you are 1 level behind things like ASI, a spellcaster level or getting a major class feature such as second attack. In general good levels to MC at are level 2,5,7 (as fighter), and 9. Sometimes missing out on an ASI/feat is fine as long as whatever you are gaining is better than a lost feat/ASI. In general classes that are martial based MC well together (eg Fighter, Ranger, Rogue) and even levels and/ore every 3 level are good for 1/3rd and 1/2 spellcasters such as Rangers, Paladins, Eldritch Knights and Arcane Tricksters. For example if you took 6 levels of fighter as an eldritch Knight and wanted to MC into a wizard that is a great cut off point as you pick up an ASI at level 6 and it counts as 2 levels of wizard for the MC spellcaster table. Level 12 would also be another decent MC point for an Eldritch Knight into wizard as you acquire your 3rd attack (your 4th attack may as well be the moon). Giving up a 3rd attack as an MC fighter can be worth it as long as you are happy with the trade off of what you are MCing into. OMe higher level fighter, Ranger and Rogue abilities are often underwhelming so MCIng can be a very good option of them such a a Rogue 8 taking the next 5 levels of Ranger or fighter. You're not giving up much and 5 levels of hunter ranger for example can offer a lot to a Rogue such as a combat type, hunters quarry spell, and possibly 3 attacks a round (2 at ranger 5+ hordebreaker) which triples your chances of a sneak attack. You end up dealing more damage than gaining an extra 3d6 sneak attack.
Another reason to MC is to get better saving throws. Some saves in the game are not very good for example a wizard and Rogue saves are sub par IMHO. Picking up con saves can be worth a dip as well for spellcasters. Due to things such as universal proficiency modifier, ability to cast in armor you can often build an unusual MC character (or single class character) that is surprisingly good in a role you would not typically associate with it such as the Mountain Dwarf Sorcerer beatstick. The Sorlock is probably the best known example of such a build and I will look at that one below. The fighter/mage/cleric/rogue thing is a D&D staple I look at it more as warrior/artillery/support/skirmisher what classes they are matters less.