If a target affected by the Slow spell uses the Metamagic option Quickened Spell when casting a spell, does that spell take effect on the same turn?

Question

The Slow spell affects spellcasting:

If the creature attempts to cast a spell with a casting time of 1 action, roll a d20. On an 11 or higher, the spell doesn’t take effect until the creature’s next turn, and the creature must use its action on that turn to complete the spell. If it can’t, the spell is wasted.

The description of the sorcerer's Metamagic option Quickened Spell states:

When you cast a spell that has a casting time of 1 action, you can spend 2 sorcery points to change the casting time to 1 bonus action for this casting.

If a sorcerer affected by Slow casts a spell using the Quickened Spell metamagic, does the spell always take effect on the same turn?

Answer 1

RAW, yes, it does take effect that turn. The spell's casting time becomes 1 bonus action so it is not affected by the Slow spell.

Answer 2

There's been a discussion about topic similar enough to this question - if a spell that takes a bonus action is affected by Slow

It does have some interesting insight on the wording and I think it does result in an outcome which seems pretty fair.

As requested, here's the replication of the argument from NautArch:

• Slow has two important effects

  1. If the creature attempts to cast a spell with a casting time of 1 action, roll a d20...

  The wording here specifies 1 action, not 1 bonus action. It also does not change the casting time itself, just when the spell would take effect, if it still cost 1 action. Therefore a Quickened spell, which now costs 1 bonus action, should no longer be affected. It takes effect normally and you don't need to use an action next turn to complete it.

  2. On its turn, it can use either an action or a bonus action, not both

  Because of this, you either use 1 bonus action for Quickened spell or do something else with 1 action, but not both.

By limiting caster under Slow effect to be only able to use action or bonus action, and caster being able to cast the Quickened spell as a bonus action, but not do anything else, the effects would cancel each other out.