Certain game features let you take a special action, called a reaction, in response to some event. Making opportunity attacks and casting the shield spell are two typical uses of reactions. If you’re unsure when a reaction occurs in relation to its trigger, here’s the rule: the reaction happens after its trigger completes, unless the description of the reaction explicitly says otherwise.
Once you take a reaction, you can’t take another one until the start of your next turn.
Does that mean a Paladin first has to declare If He uses divine smite after a hit and afterwards the enemy chooses whether He casts shield as a reaction, what might turn the Hit into a Miss?
Or is divine smite a special rule suspending the general rule?
This applies to all reactions that might turn hits into misses in relation to all feats to be used on a hit.
You cast Shield when you would have been hit, and add +5 AC, possibly making it miss. That's when the reaction occurs. I read that as the attack hasn't hit yet, and you can smite (or not) after that.
*edit* Actually I think there might be two possibilities:
a) You are correct. The paladin hits, and can then smite, and the reaction happens after all this is determined.
b) Hit means something specific, essentially a successful start-rolling-damage hit. And smite dice are added after the attack is deemed successful and nothing can effect whether it hit or not anymore.
It comes down to the definition of 'hit', which I don't believe I've seen anywhere.
The point of things being used on a hit like divine smite is that the player cannot waste them - there is no such thing as spending a spell slot on divine smite and having missed on the attack.
There is no reason for a reaction which turns a hit into a miss, like shield does to have a timing in relation to effects like divine smite that affects them in any way other than making the hit that they require before they can be used to have effectively not happened.
If the trigger of the shield spell is an attack, not a hit, that could speak for resolving the reaction before the Attacker knows if he has hit and has to declare his smite.
If the trigger of the shield spell is the hit and smite is part of the Attack/hit-action the XGtE clarification could lead to the attacker having to finish his action therefore declaring the Smite (or Not) and only afterwards the reaction would take place (that explicitely affects the triggering attack).
Take a look at the first line of the description of Divine Smite:
Starting at 2nd level, when you hit a creature with a melee weapon attack, you can...
The attack roll and interaction with the shield spell is all part of determining whether the attack hits or not, so needs to be fully resolved prior to making a decision over whether to use Divine Smite.
Sorry to re-open an ancient issue here but this recently came up at my table and I couldn't find any more recent rulings. Yes the text on smite, as you have pointed out states "...when you hit a creature with a melee weapon attack, you can expend one spell slot...", however in the text on Shield it states under the additional info to when the reaction occurs "which you take when you are hit by an attack...", so they both have the same trigger, when a hit is declared. But there is no hard order of operations, and the smite expends the spell when the paladin declares it.
So if a hit is declared, and the pally says "I'm smiting", doesn't the shield user still have the option to react with shield, and potentially turn that hit into a miss?
I think the Shield spell rules override the Smite spell rules here. And there might not be an issue after all. Let me explain how I see it.
Paladin attacks, the attack hits
Paladin then has to decide to smite or not to smite. Since a hit has been registered.
The target registers a hit on his character. The same hit that allowed for a potential smite.
Now the special rule of a Shield spell comes in. It allows to increase armor when hit, to potentially negate that hit and any effects loaded into that hit.
As I see it, Shield spells allows to potentially waste a paladin spell slot by negating a hit.
The rules for smite and shied have not changed since stormknights post. While is isn't sage advise I agree with the interpretation.
Smite is "when you hit" not when you "would hit if the creature doesn't use a reaction to prevent it", if you decide to smite and then the reaction is used to cast shield there is no hit so the paladin can not have used a divine smite and you end up with a paradox
Shield says "When you would have been hit" and makes not referance to knowing what the damage is. Therefore as soon a the paldin rolls to hit above your AC the trigger has been met and you have to decide whether to cast shield. On a non paladin attack you have to decide whether to use shield before the damage dice are rolled in the cast of a paladine the decision at to what the damage dice will be.
Yeah, I tend to agree that the smite can't be undone.
I would not, as a GM, force the paladin to commit to smiting until the hit was confirmed, because that's the only way to trigger the ability. I'd give the chance for the defender to cast shield; if no, only then is the hit actually going to happen.
RAW are definitely not sorted out though; it's a conflict of wording.
Both shield and the effect of Divine Smite trigger on a "hit." I understand the notion of not wanting to force the smite decision until everyone is sure it's going to stay a hit, but that's not the actual trigger. The trigger is a hit, and that has definitely occurred, or else you wouldn't be able to cast shield. The question is whether Divine Smite, which requires no action, or Shield, which requires a reaction, has temporal precedence.
Luckily, Xanathar's Guide to Everything has a bit of guidance for us: "If two or more things happen at the same time on a character or monster’s turn, the person at the game table — whether player or DM — who controls that creature decides the order in which those things happen." This would suggest that two responses to the same trigger happen in an order determined by whoever's turn it is; in this case, the attacking paladin, who may choose to delay their effect until after the effect of the shield spell has been determined.
I'd have to say that the precedence in order would go to shield.
A paladin can only use smite on a hit, not a potential hit or a possible hit. The paladin has to have actually hit the target in order to expend a spell slot on a smite. If they don't roll damage, no spell slot was expended since smite REQUIRES that a hit be obtained.
In the current situation, the paladin rolls to hit, their attack may be sufficient to hit the target. The target then has the option to use shield or other effects to mitigate the hit. If any of these turn the hit into a miss then the paladin has not hit and a smite is not possible. If the paladin spoke out of turn saying "I will smite" before the hit was confirmed - it doesn't change the fact that smiting still requires a hit be achieved. If something makes the attack miss then the smite simply does not happen since no hit was obtained.
I'd have to say that the precedence in order would go to shield.
A paladin can only use smite on a hit, not a potential hit or a possible hit. The paladin has to have actually hit the target in order to expend a spell slot on a smite. If they don't roll damage, no spell slot was expended since smite REQUIRES that a hit be obtained.
Again, shield can also only be cast on a hit, not a potential hit or a possible hit. The shield spell requires that a hit be obtained. It's not intuitive, but it's also not ambiguous.
Both shield and the effect of Divine Smite trigger on a "hit." I understand the notion of not wanting to force the smite decision until everyone is sure it's going to stay a hit, but that's not the actual trigger. The trigger is a hit, and that has definitely occurred, or else you wouldn't be able to cast shield. The question is whether Divine Smite, which requires no action, or Shield, which requires a reaction, has temporal precedence.
Luckily, Xanathar's Guide to Everything has a bit of guidance for us: "If two or more things happen at the same time on a character or monster’s turn, the person at the game table — whether player or DM — who controls that creature decides the order in which those things happen." This would suggest that two responses to the same trigger happen in an order determined by whoever's turn it is; in this case, the attacking paladin, who may choose to delay their effect until after the effect of the shield spell has been determined.
Yes, this makes sense. Note the text: interestingly, the decision is made out of character, despite having in-character consequences. This means a paladin's smite will normally go after shield, because that's the only sane choice, but e.g. if the paladin is only smiting due to the Enemies Abound spell, because the timing is determined out of character, the paladin's controller can decide to force smite to go first, in the hopes of wasting spell slots to mitigate how bad Enemies Abound will be.
The way I see it, while both are triggered by a hit, Shield affects the attack, while Divine Smite affects the damage.
Before you can deal damage to the target you must first resolve the attack roll. Regardless of the order of declaration, Shield is the only ability here that affects the attack roll and so must take precedence. If the result is that the attack now misses then the trigger for Divine Smite no longer exists and the ability (and spell slot) are not used.
Smite's effect applying to damage is mechanically irrelevant though. You declare it AND choose to expend the spell slot upon the hit occurring, not upon dealing the damage. So if a subsequent effect then causes that hit to become a miss, you have already expended the spell slot resource upon your declaration of a hit. Perhaps I'm too much of an MTG nerd for this, but it's so burned into my mind that you pay the cost on declaration, and you're stuck with that regardless of outcome. But the way I see it:
1. A hit occurs. Both Paladin & Caster have the option to declare effects that trigger on a hit. (I'm not going to deal with the meta of who says what first here)
2. Paladin declares a smite, upon declaring they are smiting, as per the text of the ability, they expend their spell slot.
3. Caster has still been hit, and damage has not resolved, so they still have the ability to expend their reaction and gain +5AC, potentially turning that hit into a miss.
4. Re-check for a hit, if the roll no longer meets the improved AC of the caster, the attack is a miss and play continues.
I have never encountered a situation in D&D where one character's ability choices might causes a different character to regain their spent resources. Happy to be proven wrong, I really feel like we need the old JC to give a clarification on this as it does apply to a number of different abilities (Arcane Deflection, Chronal Shift, etc.) that can alter a hit after the fact.
I think the Shield spell rules override the Smite spell rules here. And there might not be an issue after all. Let me explain how I see it.
Paladin attacks, the attack hits
Paladin then has to decide to smite or not to smite. Since a hit has been registered.
The target registers a hit on his character. The same hit that allowed for a potential smite.
Now the special rule of a Shield spell comes in. It allows to increase armor when hit, to potentially negate that hit and any effects loaded into that hit.
As I see it, Shield spells allows to potentially waste a paladin spell slot by negating a hit.
Just want to point out that the order of your bullets here are entirely arbitrary. You could swap the second and last bullets and have just as strong an argument in the other direction.
I'm with swamp_slug on this that the order of operations is 1) determine if an attack hits or misses, and only then 2) roll for damage and other effects of the successful attack. However, to my surprise I can't find any straightforward mention of this in 5e, so I can't say it's entirely invalid to rule the other way. But I can say that I believe very strongly that the RAI behind smite is that it was designed to always apply and if a DM negated my smite with a Shield I would feel cheated regardless of rules ambiguity.
Yeah the order of the bullet points are not arbitrary, other situations can occur, I'm talking about this specific situation occurring. You could absolutely have a different situation occurring, and then the paladin would have the benefit of knowing a shield is being cast before they decide whether to invest their resources. If a paladin attacks and a target uses shield, the paladin would be foolish not to wait to re-confirm the hit before deciding to use their ability. But Divine Smite specifies that the spell slot is used on declaration, not on damage. Leaving space after that for another ability to be used prior to resolving damage.
I'd have to say that the precedence in order would go to shield.
A paladin can only use smite on a hit, not a potential hit or a possible hit. The paladin has to have actually hit the target in order to expend a spell slot on a smite. If they don't roll damage, no spell slot was expended since smite REQUIRES that a hit be obtained.
In the current situation, the paladin rolls to hit, their attack may be sufficient to hit the target. The target then has the option to use shield or other effects to mitigate the hit. If any of these turn the hit into a miss then the paladin has not hit and a smite is not possible. If the paladin spoke out of turn saying "I will smite" before the hit was confirmed - it doesn't change the fact that smiting still requires a hit be achieved. If something makes the attack miss then the smite simply does not happen since no hit was obtained.
You've changed my mind and I agree with what you wrote here.
I'd have to say that the precedence in order would go to shield.
A paladin can only use smite on a hit, not a potential hit or a possible hit. The paladin has to have actually hit the target in order to expend a spell slot on a smite. If they don't roll damage, no spell slot was expended since smite REQUIRES that a hit be obtained.
In the current situation, the paladin rolls to hit, their attack may be sufficient to hit the target. The target then has the option to use shield or other effects to mitigate the hit. If any of these turn the hit into a miss then the paladin has not hit and a smite is not possible. If the paladin spoke out of turn saying "I will smite" before the hit was confirmed - it doesn't change the fact that smiting still requires a hit be achieved. If something makes the attack miss then the smite simply does not happen since no hit was obtained.
You've changed my mind and I agree with what you wrote here.
Deciding that order precedence goes to shield in this context is completely arbitrary - both smite and shield react to hit in the exact same way and with the exact same timing. Neither one cares more about being hit than the other. SagaTympana's quote from Xanathar's is the only RAW way I see to resolve it, which means which one takes precedence depends on whose turn it is.
Note the wording from Xanathar's: if a paladin smites a wizard with shield when it's neither of their turns, perhaps due to Dissonant Whispers, active controller determines precedent order - e.g. if this happens on the party bard's turn, the party bard's player determines order of operations.
I'd have to say that the precedence in order would go to shield.
A paladin can only use smite on a hit, not a potential hit or a possible hit. The paladin has to have actually hit the target in order to expend a spell slot on a smite. If they don't roll damage, no spell slot was expended since smite REQUIRES that a hit be obtained.
In the current situation, the paladin rolls to hit, their attack may be sufficient to hit the target. The target then has the option to use shield or other effects to mitigate the hit. If any of these turn the hit into a miss then the paladin has not hit and a smite is not possible. If the paladin spoke out of turn saying "I will smite" before the hit was confirmed - it doesn't change the fact that smiting still requires a hit be achieved. If something makes the attack miss then the smite simply does not happen since no hit was obtained.
You've changed my mind and I agree with what you wrote here.
Deciding that order precedence goes to shield in this context is completely arbitrary - both smite and shield react to hit in the exact same way and with the exact same timing. Neither one cares more about being hit than the other. SagaTympana's quote from Xanathar's is the only RAW way I see to resolve it, which means which one takes precedence depends on whose turn it is.
Note the wording from Xanathar's: if a paladin smites a wizard with shield when it's neither of their turns, perhaps due to Dissonant Whispers, active controller determines precedent order - e.g. if this happens on the party bard's turn, the party bard's player determines order of operations.
No. It isn't arbitrary.
Shield can turn a hit into a miss. Smite can not.
Smite can only be triggered when the paladin actually hits. If shield prevents an attack from hitting then the hit NEVER happened and smite is impossible.
"If you’re unsure when a reaction occurs in relation to its trigger, here’s the rule: the reaction happens after its trigger completes, unless the description of the reaction explicitly says otherwise."
The reaction happens AFTER its trigger completes. On a possible hit, shield can be cast or not. If shield is cast then the hit may retroactively becomes a miss. If shield is not cast then the hit stands. The trigger for smite is a HIT while the trigger for shield is a POSSIBLE hit that could be canceled by the effect of the shield spell.
Waiting for the trigger to complete for smite is waiting to determine whether a hit actually occurred or not. That is RAW based on the Xanathar's quote. If an attack ACTUALLY hits then the paladin can use smite. If an attack does not hit then smite is not possible.
The aspect that you seem to be missing is that a "hit" does not actually occur until AFTER any abilites that could mitigate that hit have been resolved (i.e. the trigger completes) - until those are resolved the "hit" is just a possible or potential hit. AFTER resolving the effect of shield or similar abilities THEN it is known whether the possible hit is actually a hit or a miss. At this point the trigger for smite is complete (not before) and the paladin can choose to smite or not knowing that the attack WAS a hit or not.
P.S. Anyway, that is how I run it and I think it is supported by RAW. I also don't like making players feel bad by forcing them to waste resources when that is clearly (to me) not the intended use of smite.
This rule clarification ist found in XGtE:
Reaction Timing
Certain game features let you take a special action, called a reaction, in response to some event. Making opportunity attacks and casting the shield spell are two typical uses of reactions. If you’re unsure when a reaction occurs in relation to its trigger, here’s the rule: the reaction happens after its trigger completes, unless the description of the reaction explicitly says otherwise.
Once you take a reaction, you can’t take another one until the start of your next turn.
Does that mean a Paladin first has to declare If He uses divine smite after a hit and afterwards the enemy chooses whether He casts shield as a reaction, what might turn the Hit into a Miss?
Or is divine smite a special rule suspending the general rule?
This applies to all reactions that might turn hits into misses in relation to all feats to be used on a hit.
You cast Shield when you would have been hit, and add +5 AC, possibly making it miss. That's when the reaction occurs. I read that as the attack hasn't hit yet, and you can smite (or not) after that.*edit* Actually I think there might be two possibilities:
a) You are correct. The paladin hits, and can then smite, and the reaction happens after all this is determined.
b) Hit means something specific, essentially a successful start-rolling-damage hit. And smite dice are added after the attack is deemed successful and nothing can effect whether it hit or not anymore.
It comes down to the definition of 'hit', which I don't believe I've seen anywhere.
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The point of things being used on a hit like divine smite is that the player cannot waste them - there is no such thing as spending a spell slot on divine smite and having missed on the attack.
There is no reason for a reaction which turns a hit into a miss, like shield does to have a timing in relation to effects like divine smite that affects them in any way other than making the hit that they require before they can be used to have effectively not happened.
I think there are two ways to See ist:
If the trigger of the shield spell is an attack, not a hit, that could speak for resolving the reaction before the Attacker knows if he has hit and has to declare his smite.
If the trigger of the shield spell is the hit and smite is part of the Attack/hit-action the XGtE clarification could lead to the attacker having to finish his action therefore declaring the Smite (or Not) and only afterwards the reaction would take place (that explicitely affects the triggering attack).
I think that this is being over-complicated.
Take a look at the first line of the description of Divine Smite:
The attack roll and interaction with the shield spell is all part of determining whether the attack hits or not, so needs to be fully resolved prior to making a decision over whether to use Divine Smite.
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Sorry to re-open an ancient issue here but this recently came up at my table and I couldn't find any more recent rulings. Yes the text on smite, as you have pointed out states "...when you hit a creature with a melee weapon attack, you can expend one spell slot...", however in the text on Shield it states under the additional info to when the reaction occurs "which you take when you are hit by an attack...", so they both have the same trigger, when a hit is declared. But there is no hard order of operations, and the smite expends the spell when the paladin declares it.
So if a hit is declared, and the pally says "I'm smiting", doesn't the shield user still have the option to react with shield, and potentially turn that hit into a miss?
I think the Shield spell rules override the Smite spell rules here. And there might not be an issue after all. Let me explain how I see it.
As I see it, Shield spells allows to potentially waste a paladin spell slot by negating a hit.
Altrazin Aghanes - Wizard/Fighter
Varpulis Windhowl - Fighter
Skolson Demjon - Cleric/Fighter
The rules for smite and shied have not changed since stormknights post. While is isn't sage advise I agree with the interpretation.
Smite is "when you hit" not when you "would hit if the creature doesn't use a reaction to prevent it", if you decide to smite and then the reaction is used to cast shield there is no hit so the paladin can not have used a divine smite and you end up with a paradox
Shield says "When you would have been hit" and makes not referance to knowing what the damage is. Therefore as soon a the paldin rolls to hit above your AC the trigger has been met and you have to decide whether to cast shield. On a non paladin attack you have to decide whether to use shield before the damage dice are rolled in the cast of a paladine the decision at to what the damage dice will be.
Yeah, I tend to agree that the smite can't be undone.
I would not, as a GM, force the paladin to commit to smiting until the hit was confirmed, because that's the only way to trigger the ability. I'd give the chance for the defender to cast shield; if no, only then is the hit actually going to happen.
RAW are definitely not sorted out though; it's a conflict of wording.
Both shield and the effect of Divine Smite trigger on a "hit." I understand the notion of not wanting to force the smite decision until everyone is sure it's going to stay a hit, but that's not the actual trigger. The trigger is a hit, and that has definitely occurred, or else you wouldn't be able to cast shield. The question is whether Divine Smite, which requires no action, or Shield, which requires a reaction, has temporal precedence.
Luckily, Xanathar's Guide to Everything has a bit of guidance for us: "If two or more things happen at the same time on a character or monster’s turn, the person at the game table — whether player or DM — who controls that creature decides the order in which those things happen." This would suggest that two responses to the same trigger happen in an order determined by whoever's turn it is; in this case, the attacking paladin, who may choose to delay their effect until after the effect of the shield spell has been determined.
I'd have to say that the precedence in order would go to shield.
A paladin can only use smite on a hit, not a potential hit or a possible hit. The paladin has to have actually hit the target in order to expend a spell slot on a smite. If they don't roll damage, no spell slot was expended since smite REQUIRES that a hit be obtained.
In the current situation, the paladin rolls to hit, their attack may be sufficient to hit the target. The target then has the option to use shield or other effects to mitigate the hit. If any of these turn the hit into a miss then the paladin has not hit and a smite is not possible. If the paladin spoke out of turn saying "I will smite" before the hit was confirmed - it doesn't change the fact that smiting still requires a hit be achieved. If something makes the attack miss then the smite simply does not happen since no hit was obtained.
Again, shield can also only be cast on a hit, not a potential hit or a possible hit. The shield spell requires that a hit be obtained. It's not intuitive, but it's also not ambiguous.
Yes, this makes sense. Note the text: interestingly, the decision is made out of character, despite having in-character consequences. This means a paladin's smite will normally go after shield, because that's the only sane choice, but e.g. if the paladin is only smiting due to the Enemies Abound spell, because the timing is determined out of character, the paladin's controller can decide to force smite to go first, in the hopes of wasting spell slots to mitigate how bad Enemies Abound will be.
The way I see it, while both are triggered by a hit, Shield affects the attack, while Divine Smite affects the damage.
Before you can deal damage to the target you must first resolve the attack roll. Regardless of the order of declaration, Shield is the only ability here that affects the attack roll and so must take precedence. If the result is that the attack now misses then the trigger for Divine Smite no longer exists and the ability (and spell slot) are not used.
Smite's effect applying to damage is mechanically irrelevant though. You declare it AND choose to expend the spell slot upon the hit occurring, not upon dealing the damage. So if a subsequent effect then causes that hit to become a miss, you have already expended the spell slot resource upon your declaration of a hit. Perhaps I'm too much of an MTG nerd for this, but it's so burned into my mind that you pay the cost on declaration, and you're stuck with that regardless of outcome. But the way I see it:
1. A hit occurs. Both Paladin & Caster have the option to declare effects that trigger on a hit. (I'm not going to deal with the meta of who says what first here)
2. Paladin declares a smite, upon declaring they are smiting, as per the text of the ability, they expend their spell slot.
3. Caster has still been hit, and damage has not resolved, so they still have the ability to expend their reaction and gain +5AC, potentially turning that hit into a miss.
4. Re-check for a hit, if the roll no longer meets the improved AC of the caster, the attack is a miss and play continues.
I have never encountered a situation in D&D where one character's ability choices might causes a different character to regain their spent resources. Happy to be proven wrong, I really feel like we need the old JC to give a clarification on this as it does apply to a number of different abilities (Arcane Deflection, Chronal Shift, etc.) that can alter a hit after the fact.
Just want to point out that the order of your bullets here are entirely arbitrary. You could swap the second and last bullets and have just as strong an argument in the other direction.
I'm with swamp_slug on this that the order of operations is 1) determine if an attack hits or misses, and only then 2) roll for damage and other effects of the successful attack. However, to my surprise I can't find any straightforward mention of this in 5e, so I can't say it's entirely invalid to rule the other way. But I can say that I believe very strongly that the RAI behind smite is that it was designed to always apply and if a DM negated my smite with a Shield I would feel cheated regardless of rules ambiguity.
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Yeah the order of the bullet points are not arbitrary, other situations can occur, I'm talking about this specific situation occurring. You could absolutely have a different situation occurring, and then the paladin would have the benefit of knowing a shield is being cast before they decide whether to invest their resources. If a paladin attacks and a target uses shield, the paladin would be foolish not to wait to re-confirm the hit before deciding to use their ability. But Divine Smite specifies that the spell slot is used on declaration, not on damage. Leaving space after that for another ability to be used prior to resolving damage.
You've changed my mind and I agree with what you wrote here.
Altrazin Aghanes - Wizard/Fighter
Varpulis Windhowl - Fighter
Skolson Demjon - Cleric/Fighter
Deciding that order precedence goes to shield in this context is completely arbitrary - both smite and shield react to hit in the exact same way and with the exact same timing. Neither one cares more about being hit than the other. SagaTympana's quote from Xanathar's is the only RAW way I see to resolve it, which means which one takes precedence depends on whose turn it is.
Note the wording from Xanathar's: if a paladin smites a wizard with shield when it's neither of their turns, perhaps due to Dissonant Whispers, active controller determines precedent order - e.g. if this happens on the party bard's turn, the party bard's player determines order of operations.
No. It isn't arbitrary.
Shield can turn a hit into a miss. Smite can not.
Smite can only be triggered when the paladin actually hits. If shield prevents an attack from hitting then the hit NEVER happened and smite is impossible.
"If you’re unsure when a reaction occurs in relation to its trigger, here’s the rule: the reaction happens after its trigger completes, unless the description of the reaction explicitly says otherwise."
The reaction happens AFTER its trigger completes. On a possible hit, shield can be cast or not. If shield is cast then the hit may retroactively becomes a miss. If shield is not cast then the hit stands. The trigger for smite is a HIT while the trigger for shield is a POSSIBLE hit that could be canceled by the effect of the shield spell.
Waiting for the trigger to complete for smite is waiting to determine whether a hit actually occurred or not. That is RAW based on the Xanathar's quote. If an attack ACTUALLY hits then the paladin can use smite. If an attack does not hit then smite is not possible.
The aspect that you seem to be missing is that a "hit" does not actually occur until AFTER any abilites that could mitigate that hit have been resolved (i.e. the trigger completes) - until those are resolved the "hit" is just a possible or potential hit. AFTER resolving the effect of shield or similar abilities THEN it is known whether the possible hit is actually a hit or a miss. At this point the trigger for smite is complete (not before) and the paladin can choose to smite or not knowing that the attack WAS a hit or not.
P.S. Anyway, that is how I run it and I think it is supported by RAW. I also don't like making players feel bad by forcing them to waste resources when that is clearly (to me) not the intended use of smite.