Tandem Casting

You have learned certain spells that have a strategic advantage when combined. It is at the DM's discretion which spells are considered compatible. Tandem spells can have a difference of up to 1 level. Tandem spells also use 2 spell slots of an appropriate level for each spell. The spells must have at least 1 damage type/effect in common, and must make sense to work together. For example, Purify food and drink can be tandem cast with Create food and water (Although this can only be done by a cleric, paladin, artificer, or circle of the desert druid.), While Ice Knife and Firebolt cannot be tandem cast.