Can a multiclass character use either of its spellcasting modifiers for spells? [duplicate]

Say someone multiclasses Wizard into Warlock, when casting a spell, which modifier do you use? Or do you use whichever you prefer?

Is it the same for exclusive spells too? Like using Eldritch Blast, can you use your intelligence modifier instead of charisma?

marked as duplicate by NautArch dnd-5e StackExchange.ready(function() { if (StackExchange.options.isMobile) return; $('.dupe-hammer-message-hover:not(.hover-bound)').each(function() { var$hover = $(this).addClass('hover-bound'),$msg = $hover.siblings('.dupe-hammer-message');$hover.hover( function() { $hover.showInfoMessage('', { messageElement:$msg.clone().show(), transient: false, position: { my: 'bottom left', at: 'top center', offsetTop: -7 }, dismissable: false, relativeToBody: true }); }, function() { StackExchange.helpers.removeMessages(); } ); }); }); Oct 2 '18 at 18:46

• – NautArch Oct 2 '18 at 18:33
• – NautArch Oct 2 '18 at 18:40

Use the modifier of the class the spell comes from

Each spell you learn comes from its own class and is labelled as such (a spell learned from Pact Magic is a warlock spell). You must use the spellcasting modifier from that class's feature.

Pact Magic

[…]

Charisma is your spellcasting ability for your warlock spells

[emphasis mine]

Even if a spell could have been learned from either class, what matters is how the individual learned it. If the character learned a spell from the wizard feature then it is a wizard spell and uses Intelligence even if it appears on other spell lists.

The Multiclassing rules detail that you treat your spells known or prepared separately for each class:

You determine what spells you know and can prepare for each class individually, as if you were a single-classed member of that class

• What about things like Chromatic Orb which is for both Sorcerer and Wizard? Which modifier would you use then? – Cyanic Oct 2 '18 at 18:36
• @guest it's not about the spell list it's from. It's bout where you learned it. If you got the spell from your Sorcerer levels, use charisma. If it's in your Spellbook and prepared use Intelligence. If you have it from both sources you can choose – David Coffron Oct 2 '18 at 18:37