Scrolls and readying an action

[Renen]

When you ready an action to cast a spell, you cast it, and concentrate on it until you can release it as a reaction (if I'm not mistaken). Which means if the trigger for the reaction doesn't happen, you waste a spell slot. Would it be the same when casting from a scroll? Or would you just not use the scroll until you read it as a reaction, thus activating it.

[utopus]

Per the DMG errata: Casting the spell by reading the scroll requires the spell’s normal casting time

This means that you can cast scroll of shield as a reaction, but you can't ready your action to cast for instance, a scroll of chromatic orb as this would be attempting to cast an action spell using your reaction, which conflicts with the above specific rule

[Tanarii]

Per the DMG errata: Casting the spell by reading the scroll requires the spell’s normal casting time

This means that you can cast scroll of shield as a reaction, but you can't ready your action to cast for instance, a scroll of chromatic orb as this would be attempting to cast an action spell using your reaction, which conflicts with the above specific rule
By that logic, you cannot Ready an Action to cast a spell, since it requires replacing the normal casting time of the spell with a reaction.

[utopus]

It's specifically with regards to spell scrolls and spell scrolls alone

[Renen]

The way I see readying a spell is you cast it using your action as normal, except you "hold it", concentrating on it until you fire it off when the trigger happens. And if it doesn't happen fast enough, you lose the spell slot cuz you cast it, but didn't fire it off fast enough. My question is if using a scroll you cast it during your turn, and then just "hold it" or if you cast it at the time of the trigger for readied action.

[Tanarii]

I've never had it come up, but I'd probably go with no. You use the action to use the scroll when you take the action. But if players started abusing it I'd change that.

Tweet Crawford. See what he thinks.