Note, you can still cast more than one leveled spell using several other methods, including but not limited to:
Combing a quicked spell with activating a magic item such as a wand or ring.
Using Action Surge
Using Thieves Reflexes
Using AoOs (one before and one after your action, then again after another action ifusing Thieves Reflexes)
Using a Contigency Spell
Hireling/other companion.
I wanted to make a quick comment about 1, then felt compelled to point out/explain various other things.
1) Note that most magic items just let you cast a spell and that follows all the normal spellcasting rules (including the topic of the thread). These include things like spell scrolls for example. Potions are an example of items that give a spell effect without casting so actually do get around the restriction.
2) True though only if you are not casting with your bonus action (the action surge follows the same restriction as regular action).
3/4/6) Is casting multiple spells per round, but not in a single turn.
5) works because the contingent spell is not technically cast, it is just when it takes effect.
I wanted to make a quick comment about 1, then felt compelled to point out/explain various other things.
1) Note that most magic items just let you cast a spell and that follows all the normal spellcasting rules (including the topic of the thread). These include things like spell scrolls for example. Potions are an example of items that give a spell effect without casting so actually do get around the restriction.
2) True though only if you are not casting with your bonus action (the action surge follows the same restriction as regular action).
3/4/6) Is casting multiple spells per round, but not in a single turn.
5) works because the contingent spell is not technically cast, it is just when it takes effect.
Not if the activation makes you cast a spell.