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I would really love to play wizard/warlock multiclass with low charisma (just 13 for mutliclass). The handbook says that I can use Pact Magic slots to cast wizard spells, but doesn't specify which ability I use for spellcasting.
If you have both the Spellcasting class feature and the Pact Magic class feature from the warlock class, you can use the spell slots you gain from the Pact Magic feature to cast spells you know or have prepared from classes with the Spellcasting class feature, and [vice versa].
When I cast wizard spells using Pact Magic slots (or warlock spells using wizard's "Spellcasting" slots) do I use spellcasting ability of the slot, or do I get to choose?