The Case for Keeping It Simple
Multiclassing is one of those systems that looks like pure upside until you’re sitting at the table wondering why your character feels like a Swiss Army knife with a broken corkscrew. More options, yes. More power, not usually.
The honest trade is this: you get breadth, you give up depth. Your class level will almost always be lower than your character level, which means Channel Divinity, Extra Attack, spell progression, and most class features scale off a number that’s perpetually behind where single-classed characters sit. That’s the cost. Whether it’s worth it depends entirely on what you’re building toward.
The Rule That Actually Changes Everything
Cantrips scale with character level, not class level. If you’re triple-classing and your character level is 9, your Fire Bolt hits like a level 9 caster’s Fire Bolt regardless of how many wizard levels are actually in that total. That’s not a footnote; it’s a genuine optimization opportunity that most people miss when they first start piecing together a multiclass build.
The Warlock interaction is the other one worth knowing cold. Pact Magic spell slots and standard spell slots are interchangeable when it comes to casting. Your Warlock slots can fire off Wizard spells, and your regular slots can power Warlock spells. Every other spellcasting class keeps its lists completely separate, oil and water, but the Warlock gets to blur that line. It’s one of the few places where multiclassing actually hands you something rather than taking something away.
How to Not Build Hot Garbage
There is a cautionary tale buried in this episode about a player who took one level in every class. His character could gesture vaguely at every skill in the game and execute none of them. It’s a useful extreme to keep in mind.
The better approach, especially if this is your first time straying from a single class, is to let the story lead. If your Rogue has been traveling with a Cleric for three levels and you want to mechanically reflect that influence, take a dip. Commit at least two levels to any new class since level 2 is usually where the worthwhile features show up. And if it doesn’t feel right after a few sessions, most DMs would rather retcon one decision than watch a player check out of a campaign.
Read both class entries in full before committing. The proficiency tables alone on page 163 of the Player’s Handbook will save you a confused conversation mid-session.