@JeremyECrawford Can a reaction be used on my turn? E.g., using counterspell to stop another counterspell from stopping my fire bolt?
— Jay Garrick Earth 47 (@TheBusyGuy) March 15, 2016
You can use a reaction on your own turn. #DnD https://t.co/9HA0NWDpws
— Jeremy Crawford (@JeremyECrawford) March 21, 2016
Ok but according to the PHB pg 202 you can only cast 1 turn Spell per turn. Only a cantrip can be cast with a spell on the same turn.
So did Crawford forget his own rule?
This is a common misreading of PHB 202. What it’s saying is that /if/ you cast a spell as a bonus action then you can only cast a cantrip as an action for the rest of your turn.
Counterspell is a reaction and sits outside the action economy so if I simply cast fireball, that’s my action spell and I can still use counterspell as a reaction unless I use a bonus action cantrip.