I have had issues with paladins, a previous player in my group was only level 5 but with his smites he somehow manages to deal roughly 50 - 60 points of damage per round and that is without dealing a critical hit, i am pretty sure he uses a greatsword with thunderous smite, and he uses divine smite, and i am pretty sure that's illegal, but the rules dont say anything about it and i have put them up in a deadly encounter but that's just a cake walk for the paladin, divine smite requires you to spend a spell slot to use it and thunderous smite needs concentration and divine smite should cancel it out right, how should i handle this?
As long as the paladin has spell slots to burn, that's perfectly legitimate.
They don't HAVE a lot of spell slots; at level 5 the paladin has 6 spell slots for the day - and that one attack, prepping thunderous with a bonus action, hitting, and then burning a smite on the hit as well - that takes two of their spell slots. That's a third of their daily spell slot capability on a single weapon strike, in a single combat. They're going to run out pretty quickly if they keep doing it.
Using divine smite is not spellcasting, and it doesn't interfere with spells or concentration - the paladin can simply choose to burn a spell slot whenever they hit with their weapon, to deal extra damage, outside of and adding onto anything else that's going on.
What's amusing is that people often complain or caution about spellcasters being over-powered in various ways... and the game designers even put rules in specifically to impede and debilitate spellcasters in ways they don't limit other classes - and have explained that it's about preventing casters from nova-casting their spell slots into excessive damage... when, in reality, Paladin (particularly Paladin-fighter combos) has more ability to nova away all their spells slots at once for obscenely massive damage, and by the rules that's just 'fair'.
50-60 damage sounds a little high though - make sure it's being added up correctly; Thunderous Smite is 2d6 (one time only - the spell ends as soon as it deals its damage once; it doesn't continue for multiple hits), Divine Smite with a second level slot is 3d8, Greatsword is 2d6, a second hit with a second second level smite, is another 2d6 plus 3d8... all up, that looks to be averaging in the high forties for damage. Bear in mind, however, the Paladin can do that a grand total of one time each long rest, by burning both second level spell slots. After that round, they have 3 1st level slots left, so they could do it again next turn, at a reduced capacity, for an average in the high thirties... after that, though, they are completely out of spell slots, and cannot smite again until they sleep.
This is all legitimate within the rules - a spellcaster is heavily limited and restrained on the amount of slots they are permitted to use each turn... but a paladin fighter combo can happily burn off six or seven spell slots in a single turn, and no-one at wizards bats an eye. (A paladin/fighter/warlock can legitimately burn their entire spell slot reserve in a single turn through a combination of divine smite and eldritch smite, which stack legitimately, if you want to get really inane)
In terms of how to 'deal' with it; it's legal and fair, and in a way, it's kind of what Paladin is famous for doing - so there's no need to restrict the player, as long as you're sure they're adding up right and they're marking their spell slots diligently. You could, however, try spacing out their encounters over the adventuring day a bit, so that they have a couple of fights before the 'big' one for the day, to drain off some of the paladin's resources.
low level paladins (2-9) have to conserve their spell slots in a normal game, I would say add in 1-2 more encounters, and have the easier ones first. also hordes are a bit of trouble for paladins, as they are usually low health individually
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“I will take responsibility for what I have done. [...] If must fall, I will rise each time a better man.” ― Brandon Sanderson, Oathbringer.
In my point of view, I consider the "smite" as an alternative version from a magical Bludgeoning damage. So, this logic goes as is:
The act of smiting means there's something ( magical or non-magical ) smacking anything else, right ?? And by smacking, I mean, it should be a non-bladed thing crashing into any kind of surface, right ???. Then :
1) Get an spiked Bludgeoning weapon ( 1 handed or 2-handed ).
2) You should start the attacking move in a higher position and nearest to the enemy/-ies.
So, the rest is easy: JUMP + SMITE spell + The spiked Bludgeoning weapon = a WIN-WIN situation............
low level paladins (2-9) have to conserve their spell slots in a normal game, I would say add in 1-2 more encounters, and have the easier ones first. also hordes are a bit of trouble for paladins, as they are usually low health individually
I'll second this. I'm running a paladin in a game right now and every time I hit it's a calculation on whether or not it's worth using one of my slots for a smite. The more opponents I expect to face in a given day, the less I can afford to just unload freely.
Rollback Post to RevisionRollBack
Find your own truth, choose your enemies carefully, and never deal with a dragon.
"Canon" is what's factual to D&D lore. "Cannon" is what you're going to be shot with if you keep getting the word wrong.
Just as a theoretical calculation for the paladin in this case:
I assume Paladin level 5 with 18 STR Great Weapon Fighting Style Great Weapon Master
Greatsword
Thunderous Smite Spell Level 1 Devine Smite using a 2nd Level Spell Slot
Option 1 (standard attacks with one Devine Smite): Cast Thunderous Smite - 1 Bonus Action Attack 1: +7 to hit, on hit 2d6 + 2d6 + 3d8 + 4 damage (rerolling 1 and 2 on the d6; I assume here in my interpretation of the wording of Devine Smite, that Great Weapon Style is not applicaple to it, but for the Thunderous Smite) Average: 16.67 + 13.5 + 4 = 34.17 damage Attack 2: +7 to hit, on hit 2d6 + 4 damage = 12.33 average Total: 46.5 average damage using 1 level 2 and 1 level 1 spell slot
Option 2 (using the strong attack of GWM): Cast Thunderous Smite - 1 Bonus Action Attack 1: +2 to hit, on hit 2d6 + 2d6 + 3d8 + 14 damage (rerolling 1 and 2 on the d6; I assume here in my interpretation of the wording of Devine Smite, that Great Weapon Style is not applicaple to it, but for the Thunderous Smite) Average: 16.67 + 13.5 + 14 = 44.17 damage Attack 2: +2 to hit, on hit 2d6 + 14 damage = 22.33 average Total: 66.5 average damage using 1 level 2 and 1 level 1 spell slot
You can up that more if you smite on the second strike again, using up one more spell slot.
Point is, however, on level 5 you do that twice and you are emptied out of spell slots.
You should use the word "percentage" instead of "average"..... it could be a bit more understoodable, there.
P.D. : I guess you have a Master degree in Technology and Industrial manufacturing... hehehe.
No, percentage would be wrong in this context. It is the number average you would expect over an infinite number of rolls. It is a valid statistical value, you can use to determine, what is statistically better.
What I actually wanted to show, is, that depending on build and rules interpretation, 40+ DMG in one turn, is totally standard with a level 5 Paladin.
Divine smite just seems very spell like in nature, and having to spend a spell slot in order to use it.
Casting a spell doesn't break concentration unless you have to concentrate on that spell right? Even if Divine smite was considered a spell, it seems like it would still be legal
Bonus action: Basically any level-appropriate foe is very very very dead by this point, so GWM lets us attack another foe as a bonus action! 8⅓ + 4 (weapon) + 10 (feat) + 2d8 (smite) = 31⅓ expected damage, 103 total on turn 1, and that's the expectation, not the maximum. This obviously goes further with the vuman extra feat, +1 weapon etc.
So yes, the adventuring day you plan for your party should definitely incentivise the paladin to spend their slots rather than giving them the luxury of spending them all to murder the boss before it gets a turn. As mentioned above, fights with medium or large groups of adversaries will allow the rest of the group to shine - a Fireball on just 4 enemies beats the paladin's optimal damage output comfortably for a single level 3 spell slot and action, and rapidly outpaces it for groups larger than 4. (As we've assumed weapons are hitting, I've assumed that dex saves are being failed too)
I have had issues with paladins, a previous player in my group was only level 5 but with his smites he somehow manages to deal roughly 50 - 60 points of damage per round and that is without dealing a critical hit, i am pretty sure he uses a greatsword with thunderous smite, and he uses divine smite, and i am pretty sure that's illegal, but the rules dont say anything about it and i have put them up in a deadly encounter but that's just a cake walk for the paladin, divine smite requires you to spend a spell slot to use it and thunderous smite needs concentration and divine smite should cancel it out right, how should i handle this?
the way that divine smite is worded and the way spells work, from what i have read, is that when you are concentrating on a spell you cannot cast any other spells or you break concentration and essentially waste the spell slot, and the way divine smite is worded it seems like a spell since you have to spend a spell slot, so, shouldn't thunderous smite be cancelled out by divine smite?
I have had issues with paladins, a previous player in my group was only level 5 but with his smites he somehow manages to deal roughly 50 - 60 points of damage per round and that is without dealing a critical hit, i am pretty sure he uses a greatsword with thunderous smite, and he uses divine smite, and i am pretty sure that's illegal, but the rules dont say anything about it and i have put them up in a deadly encounter but that's just a cake walk for the paladin, divine smite requires you to spend a spell slot to use it and thunderous smite needs concentration and divine smite should cancel it out right, how should i handle this?
the way that divine smite is worded and the way spells work, from what i have read, is that when you are concentrating on a spell you cannot cast any other spells or you break concentration and essentially waste the spell slot, and the way divine smite is worded it seems like a spell since you have to spend a spell slot, so, shouldn't thunderous smite be cancelled out by divine smite?
That is wrong on both accounts.
First of all, Divine Smite is not a spell. It's an ability. It can't be counterspelled and creatures that are protected from spells (such as a Rakshasa or someone inside a Globe of Invulnerability's area of effect) will still be harmed by it.
Second of all, you can still take actions including casting spells while concentrating on a spell. The only thing that you can't do while maintaining concentration is cast another spell with a duration of Concentration- that will immediately cause the first spell to end.
A paladin is perfectly free to use a bonus action to cast Thunderous Smite, then use Divine Smite when it hits an opponent (which does not require an action on the paladin's part since it's part of the attack action). That is RAW and RAI.
Rollback Post to RevisionRollBack
Find your own truth, choose your enemies carefully, and never deal with a dragon.
"Canon" is what's factual to D&D lore. "Cannon" is what you're going to be shot with if you keep getting the word wrong.
the way that divine smite is worded and the way spells work, from what i have read, is that when you are concentrating on a spell you cannot cast any other spells or you break concentration and essentially waste the spell slot, and the way divine smite is worded it seems like a spell since you have to spend a spell slot, so, shouldn't thunderous smite be cancelled out by divine smite?
As far as reading goes, I'd strongly advise that you begin with the PHB, rather than any other source - There is literally nothing in the PHB, or the way any of these features are worded there that suggests that a paladin's Divine Smite ability is in any way related to casting a spell. Paladins have the 'Spellcasting' feature, which details the ways in which they cast spells, and then, completely separate to that, they have 'Divine Smite', which says only that "when you hit a creature with a melee weapon attack", you "can expend one spell slot" to deal extra damage. It does not say that you cast a spell - if you did, it would say so. All the paladin is doing is expending a portion of their limited resources.
Casting a spell also 'expends one spell slot' - it's also consuming a portion of a limited resource, but that's no reason to suppose that they are the same thing. Here's an example: You only have a certain amount of energy each day. You can expend a portion of your energy to pick up a flagon of mead and drink it. You can also expend a similar portion of your daily energy to pick up a dagger and throw it at someone. Drinking a flagon of mead is not stabbing someone, however, and there's no reason to conflate the two, even though they both require you to move your arm and expend some energy.
Under "Casting a Spell" in the PHB (Chapter 10), it begins by telling you that each spell has a block in chapter 11, listing name, school, level, casting time, range, components and duration, among other details. 'Divine Smite' is not anywhere in that list and does not possess those features, because it is not a spell.
Under 'Concentration', in the Duration section of "Casting a Spell", it succinctly describes the things that, by the rules, will break concentration, as well as specifying that other activities do not. The things it lists there are: "Casting another spell that requires concentration" - this replaces your previous concentration, ending the old spell; "Taking Damage" - this causes a constitution saving throw to keep your concentration; and, lastly, "Being Incapacitated or Killed" - because it's hard to concentrate on things when your brain isn't working.
It does mention that the DM may decide that other disruptive events can also require saves to hold onto concentration - environmental hazards are the most common other cause.
Now, with all that said... you've been informed of this a few times, and you keep coming back to your original contention, despite being corrected: It sounds like you very much *want* to classify this as a spell, regardless of the base rules or what others say... or to at least block your paladin player from burning spell smites and divine smites on the same attack. If you are the DM for the game, you can certainly make that ruling and do that, but talk with your players first - and if/when they bring up that the class was designed and balanced with the ability to do that in mind, understand that they are right. If you make this change, you are taking something away from the class that it was designed and balanced to have, and you are taking away one of the things that this class does well, without giving it back anything in return. If your table is all in agreement on doing that, that's fine! It's your game to run as you all like... But by book, several folks have described to you how it works now, with reference, and offered some advice on how to challenge one class' capabilities and resources without overwhelming others.
I'm not meaning to be harsh or come across abrasive here - it's just that it sounds very much like you've already made up your mind, no matter what anyone else here says.
While things like burning smite or thunderous smite have a minute concentration. You gotta be careful and might have to beat it into someones brain that you can only use it once during that one minute concentration period. However if they use that, they could technically expend a slot for a normal smite.
It would make an infinite back and forth because lets face it, paladins can hit hard. For the most part, all those spell slots you can look at as extra damage dice. You just gotta wear the people down a bit before a boss and limit long rests. Since who wouldn't want to be 100% before a boss fight? Yet once the spellcasters or really anyone with long rest recover abilities run low, they will try for a long rest. Which case an encounter when their armor is off is going to happen. Then you catch them with lower ac and still messed up.
Minions are useful. Add undead, especially like wrigts to the mix. Something that has enough health to not die from base damage, and deals enough to make them use resources. Only one way to teach resource management. Spells take a long time to recover, short rests let your martial people shine a bit. So you gotta let them do that.
I think this has some weakness that people have pointed out. limited uses, it requires concentration (bad for melee) and prep time. another thing is this is all melee. take advantage with your range monsters. limit single big bad guys. remember being hit they have to make a con save or lose concentration. it is extremely powerful and well that is a paladin for you but by no means is it god like. flying monsters will be his or her bane. hordes of monsters will frustrate him or her. rest will be essential for them. try minions and other problems. High AC can be an issue. if he misses... well that sucks for him because that is another chance to break concentration.
Paladins are great spikers of damage however they burn out quickly. Heroes of boss battles mediocre in most other situations. have more than one battle a day and bring on the heat. bring in a giant knowing that he will smite it down then bring in the big bad guy.
Let the Paladin shine... but make it clear that the rest shine afterwards. that's how I would play it. Once you know the paladin they are fun characters but not too broken. at the end of the day they are a melee fighter with less defense than a barbarian, less continual damage than most fighters and not as much healing as a cleric. Fighting clerics are a pain in the butt!
I still stand the best group is a group full of different clerics. one forge or war domain cleric, one life domain, one knowledge or arcane and one trickery domain... boom you can buff each other, everyone has healing, action economy with bonus actions and most can wear heavy armors! that or possibly bards... oh bards.
I have had issues with paladins, a previous player in my group was only level 5 but with his smites he somehow manages to deal roughly 50 - 60 points of damage per round and that is without dealing a critical hit, i am pretty sure he uses a greatsword with thunderous smite, and he uses divine smite, and i am pretty sure that's illegal, but the rules dont say anything about it and i have put them up in a deadly encounter but that's just a cake walk for the paladin, divine smite requires you to spend a spell slot to use it and thunderous smite needs concentration and divine smite should cancel it out right, how should i handle this?
As long as the paladin has spell slots to burn, that's perfectly legitimate.
They don't HAVE a lot of spell slots; at level 5 the paladin has 6 spell slots for the day - and that one attack, prepping thunderous with a bonus action, hitting, and then burning a smite on the hit as well - that takes two of their spell slots. That's a third of their daily spell slot capability on a single weapon strike, in a single combat. They're going to run out pretty quickly if they keep doing it.
Using divine smite is not spellcasting, and it doesn't interfere with spells or concentration - the paladin can simply choose to burn a spell slot whenever they hit with their weapon, to deal extra damage, outside of and adding onto anything else that's going on.
What's amusing is that people often complain or caution about spellcasters being over-powered in various ways... and the game designers even put rules in specifically to impede and debilitate spellcasters in ways they don't limit other classes - and have explained that it's about preventing casters from nova-casting their spell slots into excessive damage... when, in reality, Paladin (particularly Paladin-fighter combos) has more ability to nova away all their spells slots at once for obscenely massive damage, and by the rules that's just 'fair'.
50-60 damage sounds a little high though - make sure it's being added up correctly; Thunderous Smite is 2d6 (one time only - the spell ends as soon as it deals its damage once; it doesn't continue for multiple hits), Divine Smite with a second level slot is 3d8, Greatsword is 2d6, a second hit with a second second level smite, is another 2d6 plus 3d8... all up, that looks to be averaging in the high forties for damage. Bear in mind, however, the Paladin can do that a grand total of one time each long rest, by burning both second level spell slots. After that round, they have 3 1st level slots left, so they could do it again next turn, at a reduced capacity, for an average in the high thirties... after that, though, they are completely out of spell slots, and cannot smite again until they sleep.
This is all legitimate within the rules - a spellcaster is heavily limited and restrained on the amount of slots they are permitted to use each turn... but a paladin fighter combo can happily burn off six or seven spell slots in a single turn, and no-one at wizards bats an eye. (A paladin/fighter/warlock can legitimately burn their entire spell slot reserve in a single turn through a combination of divine smite and eldritch smite, which stack legitimately, if you want to get really inane)
In terms of how to 'deal' with it; it's legal and fair, and in a way, it's kind of what Paladin is famous for doing - so there's no need to restrict the player, as long as you're sure they're adding up right and they're marking their spell slots diligently. You could, however, try spacing out their encounters over the adventuring day a bit, so that they have a couple of fights before the 'big' one for the day, to drain off some of the paladin's resources.
thanks that helps a lot. :)
Divine smite just seems very spell like in nature, and having to spend a spell slot in order to use it.
low level paladins (2-9) have to conserve their spell slots in a normal game, I would say add in 1-2 more encounters, and have the easier ones first. also hordes are a bit of trouble for paladins, as they are usually low health individually
“I will take responsibility for what I have done. [...] If must fall, I will rise each time a better man.” ― Brandon Sanderson, Oathbringer.
In my point of view, I consider the "smite" as an alternative version from a magical Bludgeoning damage. So, this logic goes as is:
The act of smiting means there's something ( magical or non-magical ) smacking anything else, right ?? And by smacking, I mean, it should be a non-bladed thing crashing into any kind of surface, right ???. Then :
1) Get an spiked Bludgeoning weapon ( 1 handed or 2-handed ).
2) You should start the attacking move in a higher position and nearest to the enemy/-ies.
So, the rest is easy: JUMP + SMITE spell + The spiked Bludgeoning weapon = a WIN-WIN situation............
My Ready-to-rock&roll chars:
Dertinus Tristany // Amilcar Barca // Vicenç Sacrarius // Oriol Deulofeu // Grovtuk
I'll second this. I'm running a paladin in a game right now and every time I hit it's a calculation on whether or not it's worth using one of my slots for a smite. The more opponents I expect to face in a given day, the less I can afford to just unload freely.
Find your own truth, choose your enemies carefully, and never deal with a dragon.
"Canon" is what's factual to D&D lore. "Cannon" is what you're going to be shot with if you keep getting the word wrong.
Just as a theoretical calculation for the paladin in this case:
I assume Paladin level 5 with 18 STR
Great Weapon Fighting Style
Great Weapon Master
Greatsword
Thunderous Smite Spell Level 1
Devine Smite using a 2nd Level Spell Slot
Option 1 (standard attacks with one Devine Smite):
Cast Thunderous Smite - 1 Bonus Action
Attack 1: +7 to hit, on hit 2d6 + 2d6 + 3d8 + 4 damage
(rerolling 1 and 2 on the d6; I assume here in my interpretation of the wording of Devine Smite, that Great Weapon Style is not applicaple to it, but for the Thunderous Smite)
Average: 16.67 + 13.5 + 4 = 34.17 damage
Attack 2: +7 to hit, on hit 2d6 + 4 damage = 12.33 average
Total: 46.5 average damage using 1 level 2 and 1 level 1 spell slot
Option 2 (using the strong attack of GWM):
Cast Thunderous Smite - 1 Bonus Action
Attack 1: +2 to hit, on hit 2d6 + 2d6 + 3d8 + 14 damage
(rerolling 1 and 2 on the d6; I assume here in my interpretation of the wording of Devine Smite, that Great Weapon Style is not applicaple to it, but for the Thunderous Smite)
Average: 16.67 + 13.5 + 14 = 44.17 damage
Attack 2: +2 to hit, on hit 2d6 + 14 damage = 22.33 average
Total: 66.5 average damage using 1 level 2 and 1 level 1 spell slot
You can up that more if you smite on the second strike again, using up one more spell slot.
Point is, however, on level 5 you do that twice and you are emptied out of spell slots.
You should use the word "percentage" instead of "average"..... it could be a bit more understoodable, there.
P.D. : I guess you have a Master degree in Technology and Industrial manufacturing... hehehe.
My Ready-to-rock&roll chars:
Dertinus Tristany // Amilcar Barca // Vicenç Sacrarius // Oriol Deulofeu // Grovtuk
No, percentage would be wrong in this context. It is the number average you would expect over an infinite number of rolls. It is a valid statistical value, you can use to determine, what is statistically better.
What I actually wanted to show, is, that depending on build and rules interpretation, 40+ DMG in one turn, is totally standard with a level 5 Paladin.
Casting a spell doesn't break concentration unless you have to concentrate on that spell right? Even if Divine smite was considered a spell, it seems like it would still be legal
Trying to optimise this, using the same assumptions as Voras above:
(Level 5, 18 STR, GWM, GWF, greatsword with +2 to hit, no Thunderous Smite as RAI its dice do not benefit from GWM)
Attack: 8⅓ + 4 (weapon) + 10 (feat) + 3d8 (smite) = 35⅚ expected damage.
Extra Attack: 8⅓ + 4 (weapon) + 10 (feat) + 3d8 (smite) = 35⅚ expected damage, 71⅔ total.
Bonus action: Basically any level-appropriate foe is very very very dead by this point, so GWM lets us attack another foe as a bonus action! 8⅓ + 4 (weapon) + 10 (feat) + 2d8 (smite) = 31⅓ expected damage, 103 total on turn 1, and that's the expectation, not the maximum. This obviously goes further with the vuman extra feat, +1 weapon etc.
So yes, the adventuring day you plan for your party should definitely incentivise the paladin to spend their slots rather than giving them the luxury of spending them all to murder the boss before it gets a turn. As mentioned above, fights with medium or large groups of adversaries will allow the rest of the group to shine - a Fireball on just 4 enemies beats the paladin's optimal damage output comfortably for a single level 3 spell slot and action, and rapidly outpaces it for groups larger than 4. (As we've assumed weapons are hitting, I've assumed that dex saves are being failed too)
Flood him with kobolds rather than having him go up against a Giant.
Waste those smites on the kobolds.
the way that divine smite is worded and the way spells work, from what i have read, is that when you are concentrating on a spell you cannot cast any other spells or you break concentration and essentially waste the spell slot, and the way divine smite is worded it seems like a spell since you have to spend a spell slot, so, shouldn't thunderous smite be cancelled out by divine smite?
That is wrong on both accounts.
First of all, Divine Smite is not a spell. It's an ability. It can't be counterspelled and creatures that are protected from spells (such as a Rakshasa or someone inside a Globe of Invulnerability's area of effect) will still be harmed by it.
Second of all, you can still take actions including casting spells while concentrating on a spell. The only thing that you can't do while maintaining concentration is cast another spell with a duration of Concentration- that will immediately cause the first spell to end.
A paladin is perfectly free to use a bonus action to cast Thunderous Smite, then use Divine Smite when it hits an opponent (which does not require an action on the paladin's part since it's part of the attack action). That is RAW and RAI.
Find your own truth, choose your enemies carefully, and never deal with a dragon.
"Canon" is what's factual to D&D lore. "Cannon" is what you're going to be shot with if you keep getting the word wrong.
As far as reading goes, I'd strongly advise that you begin with the PHB, rather than any other source - There is literally nothing in the PHB, or the way any of these features are worded there that suggests that a paladin's Divine Smite ability is in any way related to casting a spell. Paladins have the 'Spellcasting' feature, which details the ways in which they cast spells, and then, completely separate to that, they have 'Divine Smite', which says only that "when you hit a creature with a melee weapon attack", you "can expend one spell slot" to deal extra damage. It does not say that you cast a spell - if you did, it would say so. All the paladin is doing is expending a portion of their limited resources.
Casting a spell also 'expends one spell slot' - it's also consuming a portion of a limited resource, but that's no reason to suppose that they are the same thing. Here's an example: You only have a certain amount of energy each day. You can expend a portion of your energy to pick up a flagon of mead and drink it. You can also expend a similar portion of your daily energy to pick up a dagger and throw it at someone. Drinking a flagon of mead is not stabbing someone, however, and there's no reason to conflate the two, even though they both require you to move your arm and expend some energy.
Under "Casting a Spell" in the PHB (Chapter 10), it begins by telling you that each spell has a block in chapter 11, listing name, school, level, casting time, range, components and duration, among other details. 'Divine Smite' is not anywhere in that list and does not possess those features, because it is not a spell.
Under 'Concentration', in the Duration section of "Casting a Spell", it succinctly describes the things that, by the rules, will break concentration, as well as specifying that other activities do not. The things it lists there are: "Casting another spell that requires concentration" - this replaces your previous concentration, ending the old spell; "Taking Damage" - this causes a constitution saving throw to keep your concentration; and, lastly, "Being Incapacitated or Killed" - because it's hard to concentrate on things when your brain isn't working.
It does mention that the DM may decide that other disruptive events can also require saves to hold onto concentration - environmental hazards are the most common other cause.
Now, with all that said... you've been informed of this a few times, and you keep coming back to your original contention, despite being corrected: It sounds like you very much *want* to classify this as a spell, regardless of the base rules or what others say... or to at least block your paladin player from burning spell smites and divine smites on the same attack. If you are the DM for the game, you can certainly make that ruling and do that, but talk with your players first - and if/when they bring up that the class was designed and balanced with the ability to do that in mind, understand that they are right. If you make this change, you are taking something away from the class that it was designed and balanced to have, and you are taking away one of the things that this class does well, without giving it back anything in return. If your table is all in agreement on doing that, that's fine! It's your game to run as you all like... But by book, several folks have described to you how it works now, with reference, and offered some advice on how to challenge one class' capabilities and resources without overwhelming others.
I'm not meaning to be harsh or come across abrasive here - it's just that it sounds very much like you've already made up your mind, no matter what anyone else here says.
While things like burning smite or thunderous smite have a minute concentration. You gotta be careful and might have to beat it into someones brain that you can only use it once during that one minute concentration period. However if they use that, they could technically expend a slot for a normal smite.
It would make an infinite back and forth because lets face it, paladins can hit hard. For the most part, all those spell slots you can look at as extra damage dice. You just gotta wear the people down a bit before a boss and limit long rests. Since who wouldn't want to be 100% before a boss fight? Yet once the spellcasters or really anyone with long rest recover abilities run low, they will try for a long rest. Which case an encounter when their armor is off is going to happen. Then you catch them with lower ac and still messed up.
Minions are useful. Add undead, especially like wrigts to the mix. Something that has enough health to not die from base damage, and deals enough to make them use resources. Only one way to teach resource management. Spells take a long time to recover, short rests let your martial people shine a bit. So you gotta let them do that.
I think this has some weakness that people have pointed out. limited uses, it requires concentration (bad for melee) and prep time. another thing is this is all melee. take advantage with your range monsters. limit single big bad guys. remember being hit they have to make a con save or lose concentration. it is extremely powerful and well that is a paladin for you but by no means is it god like. flying monsters will be his or her bane. hordes of monsters will frustrate him or her. rest will be essential for them. try minions and other problems. High AC can be an issue. if he misses... well that sucks for him because that is another chance to break concentration.
Paladins are great spikers of damage however they burn out quickly. Heroes of boss battles mediocre in most other situations. have more than one battle a day and bring on the heat. bring in a giant knowing that he will smite it down then bring in the big bad guy.
Let the Paladin shine... but make it clear that the rest shine afterwards. that's how I would play it. Once you know the paladin they are fun characters but not too broken. at the end of the day they are a melee fighter with less defense than a barbarian, less continual damage than most fighters and not as much healing as a cleric. Fighting clerics are a pain in the butt!
I still stand the best group is a group full of different clerics. one forge or war domain cleric, one life domain, one knowledge or arcane and one trickery domain... boom you can buff each other, everyone has healing, action economy with bonus actions and most can wear heavy armors! that or possibly bards... oh bards.
Divine Smite doesn't require concentration or an action. You just choose to activate it or not any time you hit with a melee attack.
Find your own truth, choose your enemies carefully, and never deal with a dragon.
"Canon" is what's factual to D&D lore. "Cannon" is what you're going to be shot with if you keep getting the word wrong.