Would Shocking Grasp prevent the target from casting Absorb Elements?

Question

If a creature uses Shocking Grasp on another creature that uses its reaction to cast Absorb Elements, will Shocking Grasp, which stops a creature from using reactions, prevent the casting of Absorb Elements since Shocking Grasp should happen first before Absorb Elements does?

Answer 1

Correct, you cannot cast absorb elements in response to shocking grasp

Reactions happen after their triggers unless specified otherwise. The trigger for absorb elements is taking damage...

Reaction which you take when you take acid, cold, fire, lightning, or thunder damage

...but when you take damage from shocking grasp, you can't cast reactions anymore:

 On a hit, the target takes 1d8 lightning damage, and it can't take reactions until the start of its next turn

This means that you never have the opportunity to cast absorb elements, as you correctly deduced.

This is different from shield because shield triggers when you are hit or counterspell which triggers when the spell is cast while absorb elements triggers when you take damage. You aren't reaction-blocked until after the hit, and shield can intercede in that hit.

Answer 2

No, the Absorb Elements reaction occurs before the trigger completes

Brief Summary

1. A reaction can precede (and even erase) its trigger, (as in the Shield spell)
2. A plain reading of Absorb Elements, shows it in effect when the triggering damage is received
3. Both effects of Shocking Grasp occur at the same time
4. The Absorb Elements reaction is in effect, before the target loses its ability to take reactions

Full Explanation

A Reaction can Precede its own Trigger

...as it does in the Shield spell:

CASTING TIME: 1 Reaction* | *- which you take when you are hit by an attack...

... Until the start of your next turn, you have a +5 bonus to AC, including against the triggering attack...

From the Casting Time, Shield can only be cast once the triggering event has already happened; yet the spell's effect ends up preceding the (hit) trigger and can even prevent the trigger from existing, (the hit was actually a miss!)

Moving past Shield to a general analysis of reactions, you notice the Casting Time on reaction spells (e.g. Feather Fall, Counter Spell, Hellish Rebuke,) all read as if the spell is cast after the trigger. But since we know reaction effects can occur before the trigger, we must look at the spell text for reaction timing.

When does Absorb Elements take effect

CASTING TIME: 1 Reaction* | * - which you take when you take acid, cold, fire, lightning, or thunder damage

The spell captures some of the incoming energy, lessening its effect on you and storing it for your next melee attack. You have resistance to the triggering damage type until the start of your next turn.

As expected, the Casting Time reads as if casting occurs after the trigger is done, but the spell text in bold explicitly narrates the damage resistance (effects) of Absorb Elements, as already in place when the damage is received.

Another Q&A and a Crawford tweet confirm that Absorb Elements is intended to effect the triggering damage.

Shocking Grasp

... On a hit, the target takes 1d8 lightning damage, and it can't take reactions until the start of its next turn.

With no text or rule to separate them, both of Shocking Grasp's effects occur at the same time. As such, any effect that occurs before the lightning damage (e.g. Absorb Elements), also occurs before the reaction debuff.

Conclusion

Absorb Elements is a defensive reaction spell that exists to trigger and reduce incoming elemental damage, before it is actually received. Since its effect precedes the damage from Shocking Grasp, it also precedes Shocking Grasp's reaction debuff.

Answer 3

No, you can cast Absorb Elements when (about to be) hit by Shocking Grasp

According to this answer (backed by Crawford), Absorb Elements applies to the triggering attack.

Q: Does Absorb Elements give you resistance to damage from the triggering attack?

A: Yes.

You cannot take damage, and then halve that damage (the damage is already taken and done with). Therefore, Absorb Elements must be cast before taking damage from the attack, which is before the effect of Shocking Grasp prevents the reaction.

Normally reactions that interrupt an attack (between roll and the effects happening) specifically call out that they are interrupting (see Shield). In Absorb Elements case it doesn't, but the only way for the spell to work as intended is for it to work the same way. This problem probably stems from the fact that Absorb Elements was published in a campaign module not a regular rulebook. Such things tend to have a lower level of Quality Assurance applied to them.

Answer 4

Specific (spell block text) > General (core rule text)

D&D is a game of exceptions, meaning (a) happens before (b) except when it doesn’t. I agree with the other answer that AE triggers before SG is completed but AE isn’t resolved until SG is resolved. Both are instantaneous effects if RiE. Both have a primary effect and a secondary effect. Primary > Secondary until you can prove otherwise.

This is a specific exception to the rules. The reaction spell casts faster than an action spell. So in the midst of SG spell effects, AE activates and begins its effects. SG then finishes it’s effects followed by AE last effects.

Spells

Casting Time

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.

Order of Resolution

1. Creature A. casts Shocking Grasp on Creature B
2. Creature B. is hit and takes (primary effect of SG) xd8 lightning damage
3. Creature B. casts Absorb Elements as a reaction, triggered by receiving lightning damage (primary effect of AE).
4. Creature A. (secondary effect of SG) target can’t use reactions til end of his next turn.
5. Creature B. (secondary effect of AE) extra d6 damage with next melee Attack on next turn.

If that’s not the case, then you have an OP Cantrip ? For it literally disables a majority of the reaction mechanic, including specifics.

Disabled by Shocking Grasp

Class Features

• Barbarian: Retaliation
• Bard: Cutting Words
• Cleric - Nature Domain: Dampen Elements
• Cleric - Tempest Domain: Wrath of the Storm
• Fighter - Battle Master: Maneuver - Parry
• Ranger - Hunter: Hunter’s Prey - Giant Killer
• Ranger - Hunter: Supeior Hunter’s Defense - Uncanny Dodge
• Rogue: Uncanny Dodge
• Warlock - Archfey: Misty Escape

Feats

• Defensive Duelist

Combat

• Reactions