To multiclass in 5e, you need to level up at least once and meet the ability score minimum prerequisite for the new class you wish to pursue. Whenever you advance a level, you have a choice of gaining that level in your current class or choosing to multiclass, gaining a 1st-level and some features belonging to the new class.
Afterward, when you gain a level, you can choose to apply it to either of your classes. You can also multiclass in several classes, although your progression in each of them will be severely hampered.
Prerequesites for Multiclassing
To multiclass, you must meet the ability score prerequisites for your current class and the new one. Here are the prerequisites:
|Class||Ability Score Minimum|
|Fighter||Strength 13 or Dexterity 13|
|Monk||Dexterity 13 and Wisdom 13|
|Paladin||Strength 13 and Charisma 13|
|Ranger||Dexterity 13 and Wisdom 13|
For example, if a Cleric wanted to multiclass into Rogue, they would need at least 13 Wisdom and Dexterity.
Proficiencies Gained from Multiclassing
You gain some of the new class’s starting proficiencies when you multiclass, as shown in the table below.
|Artificer||Light armor, medium armor, shields, thieves’ tools, tinker’s tools|
|Barbarian||Shields, simple weapons, martial weapons|
|Bard||Light armor, one skill of your choice, one musical instrument of your choice|
|Cleric||Light armor, medium armor, shields|
|Druid||Light armor, medium armor, shields (druids will not wear armor or use shields made of metal)|
|Fighter||Light armor, medium armor, shields, simple weapons, martial weapons|
|Monk||Simple weapons, shortswords|
|Paladin||Light armor, medium armor, shields, simple weapons, martial weapons|
|Ranger||Light armor, medium armor, shields, simple weapons, martial weapons, one skill from the class’s skill list|
|Rogue||Light armor, one skill from the class’s skill list, thieves’ tools|
|Warlock||Light armor, simple weapons|
You do not gain saving throw proficiencies of the new class when multiclassing. Unless this saving throw proficiency is granted via a class or subclass feature, like a Monk’s Diamond Soul feature. (Sage Advice Compendium 7; Sage Advice thread)
Features and Multiclassing
When you level up in a class, you gain its features. So if you have 6 levels in Paladin and 1 level in Fighter, and choose to assign your next level up to increase your Fighter to 2nd level, you’ll gain the Action Surge feature when you do so (as it is a 2nd-level Fighter feature). Your character will be 8th level overall at this point.
Some features have special rules for multiclassing:
Channel Divinity. Paladins and Clerics both have Channel Divinity, but you don’t gain extra charges when you have levels in each. You just have additional Channel Divinity options to choose from.
Extra Attack. Extra Attack features don’t stack; unless you’re a higher-level Fighter, you max out at one Extra Attack.
Unarmored Defense. Monks and Barbarians have Unarmored Defense, but you can’t gain it from one class if you’re multiclassing from the other.
Spellcasting. Spellcasting depends somewhat on your combined spellcasting class level. Here’s more detail:
Spells known and prepared. These things are individually determined based on the spellcasting classes. So if you have 3 levels in Cleric and 1 level in Wizard, you’d be able to prepare any Cleric spells of 1st- or 2nd-level up to a number based on your Cleric level and Wisdom modifier, and you’d know six 1st-level Wizard spells and be able to prepare a number based on your Wizard level and Intelligence modifier.
Spell slots. To determine spell slots, add up all your levels in bard, cleric, druid, sorcerer, and wizard, half your levels for artificer, paladin, and ranger (rounded down), and one-third of your levels for Eldritch Knight Fighter and Arcane Trickster Rogue. The table below shows spell slots per multiclass spellcaster level.
You may have access to higher-level spell slots than spells you can actually learn or prepare. You can still use these spell slots for lower-level spells, possibly enhancing their effects.
Pat Magic. Pact Magic and Spellcasting class feature spell slots can be used interchangeably.
Multiclass Spellcaster: Spell Slots per Spell Level
Dungeon Master’s Guide, pages 163-5