*pushes glasses even higher* That rule specifically only applies when you use a bonus action to cast a spell. (Rules link).
Two leveled spells using your actions are fine.
Here's the relevant sage advice to confirm.
While the sage advice doesn't address leveled spells in action/reaction (e.g., fireball and counterspell) in the same turn, we can assume it is possible as no bonus action is used.
No, action surge only gives you an additional action, not an additional turn. So two leveled spells and one cantrip, or two cantrips and one leveled spell.
Action Surge only gives you an additional action for the turn. Casting a Bonus Action Spell would lock off both the standard and additional action from being able to cast a leveled spell.
So, 2 Cantrips + a BA spell works.
2 leveled spells as actions works, but no BA spell even if it's a Cantrip.
I thought you can't cast 2 leveled spells in one turn though. If you could, you could just do it as a bonus action w/ metamagic. That's what I'm saying.
or does action surge actually bypass this restriction??
A spell cast with a bonus action is especially swift. You must use a bonus action on your turn to cast the spell, provided that you haven't already taken a bonus action this turn. You can't cast another spell during the same turn, except for a cantrip with a casting time of 1 action.
It only stipulates that a Spell cast as a Bonus Action locks off any Action Spells from being cast that turn that isn't a Cantrip.
But, 2 leveled spells cast as Actions is fair game.
It's pretty strong, and it's why the 1DND play test has changed Action Surge so that it can only take the Attack, Dash, Disengage, and Dodge action
The two spell thing only applies to spells cast via a bonus action. Since action surge gives you an extra action you can cast two leveled spells, whereas quickened spell just changes the casting time from an action to a bonus action.