Can you react to your own spell?

Question

During my last game, a player tried to have his character make a miraculous escape, only to wind up splattered instead. I'll provide some details, but the gist of my question is whether my ruling on action economy was incorrect.

The PC, a Level 9 sorcerer with the Quicken Spell metamagic feature, started his turn chained up in the bottom of a rowboat. His party was in the water trying to rescue him from his captors, but he was unaware of both this and the knowledge that the great white shark that had just taken a bite out of the boat was technically on his side. His plan was as follows:

1. Cast dimension door, transporting himself instantly 500 feet in the air.
2. Cast feather fall and float downward.
3. Wait out the rest of the fight safely overhead.

Now, this particular player believes in an antagonistic relationship between player and DM (he's the kind of fellow who believes that when you win, you've beaten the DM, and when he's DM it's his job to kill the players as fairly as possible). As such, he refused to tell me the next part of his plan until he had found out whether the current part had worked, so I wouldn't have time to ruin it. Which meant that his plan played out as follows:

1. His character successfully casts dimension door, reappearing 500 feet over the boat. I ask if he's sure, and he insists.
2. His attempt to cast feather fall fails, and he plummets 500 feet. I prepare to roll damage, thinking that he'll hit the water. The player grumbles.
3. One of the other players reminds me that the boat is being held in place by the shark. Both the antagonistic player and I immediately realize his character is going to hit the boat, not the water.
4. Shouting ensues. I eventually lay out the reasoning below, and then roll damage. His character deals 76 points of damage to himself, the boat, and the NPCs that had been holding him hostage. This is enough to kill his character instantly due to massive damage.

Because this reasoning killed a PC, I'd like to be sure that I have a valid interpretation of the rules, namely, whether you can cast a spell and react by casting a spell on the same turn. I provided as support that you can't the following bit from the Player's Handbook, which specifically references spells as bonus actions:

You can’t cast another spell during the same turn, except for a cantrip with a casting time of 1 action.

I reasoned that if you can't cast another spell after you cast a spell as a bonus action, that means even as a reaction. I also specified that it was specific to his turn, as it mentions, and that if he had fallen on someone else's turn it would have been quite possible to use feather fall. To drive that point home I likened it to trying to cast magic missile to hit yourself and then reacting to yourself by casting shield, which I would also disallow. Is this right? Can you cast a spell with an action or bonus action and then cast a spell as a reaction, all on your turn? Or did this particular PC legitimately outsmart himself?

For The Record:

• In my games, players take turns in sequence over the course of 6 seconds. I understand the logic of simultaneous turns, but unless everyone agreed in advance what their actions were and then the round was resolved all at once, it wouldn't work at my table... and as you can see, some players don't even want to discuss all of their turn at once.

• In my games, falling occurs on the player's turn, unless they are forced to fall by someone else's action, kind of like movement. Not worried about this but, as the player agrees that this works (and has taken advantage of the rule before).

• By a non-coincidence, falling in my games occurs at the rate of 500 feet per round. Since the falling occurred on his turn, he went up and came down all during the same turn.

Answer 1

You can normally take reactions on your own turn, which includes reacting to things you are doing to yourself.

Note though that Featherfall isn't reacting to a spell you cast; it's reacting to you falling. It shouldn't make a difference whether you step off a cliff or cast a spell; one of its designed uses is to save you from splattering when you find yourself in the air by your own choice. (The other is, obviously, when you find yourself in the air by another's choice)

However, the specific bit about Bonus actions does apply here. Since it's still the player's same turn, he could not cast Feather Fall if he cast Dimension Door as a bonus action. But he should be able to do it, had he used Dimension Door as a normal action.

For another example; while it's silly to Magic Missile yourself in the face and then Shield yourself, it's perfectly valid to Magic Missile someone else and then Shield yourself when you realize your intended target has some form of Spell Reflection.

As long as you can cast spells, you can cast those spells as a Reaction on your turn, even if the original trigger for your Reaction spell is something you did to yourself.

Answer 2

He should have been able to cast feather fall.

After my original post I read this and changed my mind on my answer. (This is my original answer.)

Per the PHB:

Reactions Some spells can be cast as reactions. These spells take a fraction of a second to bring about and are cast in response to some event. If a spell can be cast as a reaction, the spell description tells you exactly when you can do so.

Using the specific vs general rules this is a specific rule that governs spells with a casting time of 1 reaction. After he cast dimension door the trigger for his reaction was met and he should have been allowed to cast feather fall.

Answer 3

Short Answer: YES, you can react to your own spell.

• He should have been able to cast both spells. See clarification below.

or

• The entire sequence should have been ruled against and he should have started over.

There are numerous problems here.

---

The biggest problem in this scenario is the relationship between you and the player. I know you addressed it, but that doesn't mean it's not the main problem.

---

Reactions and reaction spells are allowed on your turn. There are explicit rulings allowing a wizard to cast a fireball which is then counterspelled and use their reaction to counterspell the original counterspell. So by RAW (and clarified by rulings) you should be able to shield yourself from your own magic missile. However, in this question, Feather Fall is a reaction to falling, not Dimension Door. The question in the title does not match the problem you've laid out.

---

You said that "For those curious whether Quicken Spell plays a role, literally yes and no. He asked whether using it would change my answer (it did not)."

1. If the player casts dimension door with their action, by RAW they can use their reaction to cast Feather Fall.
2. If the player casts a quickened dimension door with their action, by RAW they can only cast cantrips for the rest of their turn (including before the dimension door). In such a case you could not cast Feather Fall (a non-cantrip) as a reaction on the same turn.

By RAW you are wrong, since without the quickened spell (#1) the bonus action spell rule does not come into play, whereas with it (#2) the rule applies and spoils the fun.

---

The bonus action spell rule is very flawed. I consider it one of the worst rules in 5e because it makes no sense when you consider all of the scenarios where you can cast multiple non-cantrips vs. the scenarios where the rule comes into play. I will probably be rewriting that rule specifically for my next table. (Clearly this paragraph is my opinion, but is on-topic for the circumstances of this question.)

Since there is some confusion in some of the other answers and comments, let me be very clear. The bonus action spell rule only limits spellcasting if a spell was cast as a bonus action. It has no bearing whatsoever on casting 2 spells with 2 actions or with action & reaction.

---

For a player and DM with a good relationship, such a ruling should be clarified in advance of resolving the turn. If the character says they want to cast a spell in such a way and then cast another spell, they should be ruled against and allowed to reconsider (so long as no other creatures have already acted due to the first spell).

---

Finally, you may be holding to strict RAW (possibly due to your antagonizing player), but you have completely ruled against Rules as Fun. He burned 2 spell slots to commit suicide. That's not a fun game.

Answer 4

He would most likely die.

You correct. As per the PHB

You can’t cast another spell during the same turn, except for a cantrip with a casting time of 1 action.

Feather fall is a level 1 spell and has a cast time of 1 reaction, so he would not have been able to cast it on his turn.

So the next thing to determine would be would he have time to cast it before he hit the boat?

Per XGtE:

When you fall from a great height you instantly descend up to 500 feet. If you're still falling on your next turn you descend up to 500 feet at the end of that turn. This process continues until the fall ends.

By this rule he would have hit the boat on his turn and would have never gotten the opportunity to use a reaction on anybody else's turn.

It should be noted that is is an optional rule.