Help me resolve surprise vs alert

[No brains]

Does anyone else have trouble with Alert and surprise? I know Alert says that a creature can't be surprised, but there are some times when it is really hard to justify how they aren't surprised.

I suppose one thing that would help me is to get a clear idea of when combat begins. It's discussed in this video with JC (all over the place, so no timestamp), https://youtu.be/vS9efeyCHTc, but there are times when the trigger for combat is more complicated than drawing a dagger.

If a creature can see and move through a wall and melee attack the party without any real clues or cues, what should I do? Incorporeal movement, earth glide, truesight through illusory walls, and even just plain physical distance can really stretch the credibility of someone reacting to an attack in time. Sure people do implausible stuff in D&D all the time, but this is so implausible, I'm having trouble narrating how they do it.

My best guess is to have the Alert PC use Spider Sense/ Bullet Time right as something happens, even if it slightly breaks the order or actions happening. For example, if somebody with truesight launches an attack through an illusion and the Alert PC gets to go first, I can just have the ambushing creature commit to that attack even though they could technically change their mind. So say a blowdart comes out of the illusion and the Alert PC sees that dart coming and can Quicksilver run straight to where it came from to attack. Then I have that creature continue with its blowdart attack even though it technically can choose a better option.

Does anyone have any other ideas on how to handle this? Aside from banning Alert?

[strangebloke]

Treat it like a sixth sense.

A goblin successfully sneaks up on Aaron Lertz. He readies his arrow to fire, and then suddenly, Aaron is on his feet, sword in hand, ready to fight. Aaron doesn't see the goblin, he just 'knows' that he's about to get attacked. Maybe this spooks the goblin and he slinks away instead of fighting.

[KorvinStarmast]

Does anyone else have trouble with Alert and surprise? Nope. No problem. With Alert, the PC is not surprised. Ever. All five or six of his/her senses are superior.

It's not a problem. When determining surprise, the DM never has to see if that character is surprised. They are not.


My best guess is to have the Alert PC use Spider Sense/ Bullet Time right as something happens, even if it slightly breaks the order or actions happening.
Something like that, yes.
Roll initiative just as you would for any other first turn/round.
Combat Step by Step

1. Determine surprise. The DM determines whether anyone involved in the combat encounter is surprised.
Nothing Happens Yet!

2. Establish positions. The DM decides where all the characters and monsters are located. Given the adventurers’ marching order or their stated positions in the room or other location, the DM figures out where the adversaries are—how far away and in what direction.
Nothing Happens Yet!

3. Roll initiative. Everyone involved in the combat encounter rolls initiative, determining the order of combatants’ turns. Now, apply the surprise rule:

If you’re surprised, you can’t move or take an action on your firs t turn of the combat, and you can’t take a reaction until that turn ends. A member of a group can be surprised even if the other members aren’t.

4. Take turns. Each participant in the battle takes a turn in initiative order.

5. Begin the next round. When everyone involved in the combat has had a turn, the round ends. Repeat step 4 until the fighting stops.

[darknite]

As others have said. PCs are a cat of a different breed and can do all kinds of amazing things you'd think were impossible. A strong brew of OODA superiority - superior senses, honed reflexes and the ability to immediately choose and execute a response against a threat.

[CorporateSlave]

My best guess is to have the Alert PC use Spider Sense/ Bullet Time right as something happens, even if it slightly breaks the order or actions happening. For example, if somebody with truesight launches an attack through an illusion and the Alert PC gets to go first, I can just have the ambushing creature commit to that attack even though they could technically change their mind. So say a blowdart comes out of the illusion and the Alert PC sees that dart coming and can Quicksilver run straight to where it came from to attack. Then I have that creature continue with its blowdart attack even though it technically can choose a better option.



All Alert does is prevent the Surprised Condition on that PC. Just because the PC isn't Surprised their first Turn, doesn't mean they magically know where the enemy is, or necessarily even exactly what is happening. If you want to call it a "6th sense" where they "spidey-sense" danger that works, but it won't mean they can run over to the enemy and attack, it just means they are aware of danger and can take an Action on their Initiative (and a Reaction at any point in the Round as usual).

If the enemy Attack hasn't resolved yet, there is no blowgun dart to see yet. A good use of the PC's Action might be a Perception check to figure out what is going on, or possibly Ready an Attack for once the location of danger is known. If they are a caster, a defensive spell might be in order.

[Xeko]

It also depends on the flavor. How does the player/character treat their own alertness? Another thing to really drive home and emphasize here is that Surprise works different in 5e than in other editions. And it's probably the single biggest mistake that DMs make consistently. There are no "surprise rounds". Surprise is a status condition. Let's take Assassinate, for example. Assassinate is a rogue ability that gives the rogue an automatic critical, when they hit a surprised creature. So, the party has an Assassin rogue in it, and they get the jump on a group of goblins or whatever. The goblins are surprised. But, if the goblins roll higher initiative than the rogue does, the rogue does NOT get the auto-crit Assassinate bonus. Because by the time the rogue's turn comes up, the goblins aren't surprised anymore.

The same applies in reverse. If ANY attack is made, even an invisible or "undetectable" one, initiative MUST be rolled. If you want to be dramatic about it, you as the DM could roll initiative for the players behind the screen, without them knowing, but there should still be an initiative order. And any players that have higher initiative than the attacker simply isn't surprised by the attack. And if a character has Alert, then they aren't surprised either, even if they rolled lower in initiative. That said, just because a creature knows an attack is coming, doesn't mean they can do anything about it. A creature with Alert, who loses initiative, sees what's happening, they are not surprised, but because they lose initiative, they're too slow to get out of the way, and are likely to get hit anyway. Surprise might mean you effectively go last in combat... but not being surprised doesn't necessarily mean you go first.

Now, let's say that you DO roll initiative for the player characters, without them knowing. And a player character wins the roll. They technically get first turn. But, if they don't know that there's a threat (check their passive perception), then they're likely going to spend their turn doing whatever they were doing before the initiative roll, completely unaware that they should be doing any different. In that way, if you really want to, you can still give the attacker first action, catching the players unawares. It just means the "surprised" condition doesn't apply to it, which isn't a big deal. Ultimately, the only thing Surprise does is determine if a defending creature gets to use reactions or not. And really, aside from like, Hellish Rebuke, or opportunity attacks, there aren't a lot of reaction options in the game. So that doesn't actually matter. TECHNICALLY, surprise also gives the attacker advantage, and they wouldn't get that. But, attacking while hidden ALSO gives advantage, so the attacker would most likely have advantage anyway, so again, doesn't actually matter. The only situation I can think of, where the players being surprised or not surprised would make a significant difference is in the case of the assassin rogue. If the attacking creature is the assassin rogue subclass, they get auto-criticals when hitting a creature that is surprised. And losing that benefit might actually matter. But I can't think of any enemy creature that has that specific ability, or one like it. So, unless you're doing pvp, or homebrewing monsters, that also, again, for the third time, doesn't really matter.

[Throne12]

They have very fast reflexes and reaction time. Ya that goblin sneaked Up and got in ranged but as he is pulling his bowstring back. The alert pc hears the nearly silent creak of the bowstring pulling on the bow back.

Also time about the name of the feat Alert. The pc is so paranoid that he/she is always on alert and keeping his scenes up.

There will always be something. A faint noise or scent.

[Sigreid]

Perhaps it would help you if you thought of feats as low level supernatural abilities. There's nothing normal about the Alert adventurer's awareness of danger.

[Darkstar952]

As others have said treat it as a very minor sixth sense that just jolts them into action.

The important thing I think is to not give them too much information about the encounter that they wouldn't know, so if the alert character wins initiative then they still potentially have no idea what is attacking/happening and have to act in the absence of information.

Basically they aren't surprised and can act, but as they haven't seen anything they have no idea what they are reacting to.

[ShikomeKidoMi]

As others have said, they know "there's danger here" not "there's three goblins in this bush." But they can always take the Dodge action, use an Action to make a Perception Check, or ready something.

[Sigreid]

You can flavor it in fun ways if you want. Something like a guardian spirit that whispers in their ear "move!" Ir something.

[NNescio]

Does anyone else have trouble with Alert and surprise? I know Alert says that a creature can't be surprised, but there are some times when it is really hard to justify how they aren't surprised.

I suppose one thing that would help me is to get a clear idea of when combat begins. It's discussed in this video with JC (all over the place, so no timestamp), https://youtu.be/vS9efeyCHTc, but there are times when the trigger for combat is more complicated than drawing a dagger.

If a creature can see and move through a wall and melee attack the party without any real clues or cues, what should I do? Incorporeal movement, earth glide, truesight through illusory walls, and even just plain physical distance can really stretch the credibility of someone reacting to an attack in time. Sure people do implausible stuff in D&D all the time, but this is so implausible, I'm having trouble narrating how they do it.

My best guess is to have the Alert PC use Spider Sense/ Bullet Time right as something happens, even if it slightly breaks the order or actions happening. For example, if somebody with truesight launches an attack through an illusion and the Alert PC gets to go first, I can just have the ambushing creature commit to that attack even though they could technically change their mind. So say a blowdart comes out of the illusion and the Alert PC sees that dart coming and can Quicksilver run straight to where it came from to attack. Then I have that creature continue with its blowdart attack even though it technically can choose a better option.

Does anyone have any other ideas on how to handle this? Aside from banning Alert?

Being Surprised just means you can't act (no movement or actions) on your first turn. This includes no reactions, until you have ended said first turn. You still technically take the turn (including triggering any "start of turn"/"end of turn" effects), but you effectively skip it.

Having the Alert feat means you are never considered Surprised. It does not give you any additional information.

As DM though, I would let the player know that something bad is going on (because otherwise wasting the turn just because the player rolls high enough on Init to beat all the enemies' just feels bad. Plus the player already knows that Init has been rolled, so expecting said player to just roleplay the character twiddling its thumbs and doing nothing can be galling), but only in a vague sense. ("chills down the back", etc. for the character, "combat has started" for the player.) Usually most of them will scatter away from the party (and/or move behind cover) and use their reaction to ready a ranged attack.

So, for an ambush that no characters has managed to detect, I'll do the following:

1. Determine surprise. Creatures with the Alert feat cannot be surprised, regardless of circumstances.
2. Everyone rolls Init.
3. Everyone takes their turn in order. Surprised creatures don't get to act on their first turn, and cannot take reactions until their first turn have ended.
4. Non-surprised PCs know that "something bad is going on" ("combat has started" in the meta sense), even if they aren't aware of the enemies themselves. They gain no other information.

TL;DR: I treat "being surprised" in a ludonarrative sense as "not aware that combat has started (until it has taken its first turn)." (Note that this is not strictly RAW). A creature who is not surprised is therefore aware, and can act accordingly. It gains no other information beyond its current knowledge and what it senses.

[NaughtyTiger]

To Korvin's point:

DM initiates combat, everyone rolls initiative, and Bob the Alert rolls higher than the enemy.

Bob knows combat is imminent, but if it is an unseen attacker (through a wall, invisible, or well hidden), he doesn't know by what, and can't attack it...

it that a waste of initiative?

you can ready an action as soon as you see the bad guy, but then you only get 1 of your attacks (and depending on the DM, after the unseen attacker does it's devastating blow)
a low initiative, but unsurprised, lets you have your full range of actions.
thus he is more likely to be punished for taking the feat.

maybe the DM lets you do a free perception check to identify the target for your attack?

[NNescio]

To Korvin's point:

DM initiates combat, everyone rolls initiative, and Bob the Alert rolls higher than the enemy.

Bob knows combat is imminent, but if it is an unseen attacker (through a wall, invisible, or well hidden), he doesn't know by what, and can't attack it...

it that a waste of initiative?

you can ready an action as soon as you see the bad guy, but then you only get 1 of your attacks (and depending on the DM, after the unseen attacker does it's devastating blow)
a low initiative, but unsurprised, lets you have your full range of actions.
thus he is more likely to be punished for taking the feat.

maybe the DM lets you do a free perception check to identify the target for your attack?

You don't even get to act (on your first turn) if you didn't take the feat. And more critically for Wizards (and other squishies who rely on active defenses), you wouldn't be able to use reactions.

Alert doesn't punish players.

[NaughtyTiger]

You don't even get to act (on your first turn) if you didn't take the feat. And more critically for Wizards (and other squishies who rely on active defenses), you wouldn't be able to use reactions.

Alert doesn't punish players.

fair point, let me adjust my answer.
alert helps players with low init more than players with high init.
alert (often) doesn't help players with high init attack first.
high init squishies (IMX most casters have higher dex than enemies) have a good chance of using reactions without alert.

and there is the perception issue, that it "feels" like you are being punished cuz you have no target if you roll well.

[Keravath]

The Alert feat is like a sixth sense and enhanced senses combined with fast reaction times.
- your initiative is higher
- you can't be surprised
- attackers who are unseen by you do NOT get advantage on their attacks (this last one is useful and often goes unmentioned).

Korvin's post outlined the procedure really well explaining the steps in organizing the combat round if surprise is a possibility.

In terms of combat, all the lack of surprise does is allow the character to take an action on their first turn based on the information available to the creature at the time. If the opponents haven't attacked yet then the character still has a lot of options for what they can do.

1) They can move. Hopefully to a better position.
2) They can dodge. (likely the easiest thing to do).
3) If a creature is unseen but not hidden then they will know where it is and can attack with disadvantage.
4) If a creature is hidden then the character can STILL choose to attack any legal location (the attack is at disadvantage and if the location is empty it is an automatic miss). (For example, it is possible to fire cross bow bolts or make melee attacks in an apparently empty room in an attempt to hit a creature hidden in the room).
5) The character can cast a spell.
6) The character can ready an action with a specific trigger. e.g. I attack the first hostile creature I see.
7) The character can search likely making a perception check to try to reveal anything hidden.

From both a DM and player perspective, I have no issues with the Alert feat. It is a fun feature that is fairly well balanced and makes for an interesting character.

However, It seems to me that most often complaints about Alert are because a DM wants to have a certain narrative where the characters are forced into a course of action as a result of being surprised by overwhelming force. An Alert character sometimes makes it more likely for combat to break out in these circumstances since the Alert character can take actions, move, escape, cast spells which might cause the encounter to go down a path the DM wants to avoid. However, in this case, the issue isn't the feat but the DM trying to force a specific narrative outcome and trying to work around a character ability that makes it more difficult.

[NaughtyTiger]

An Alert character sometimes makes it more likely for combat to break out in these circumstances since the Alert character can take actions, move, escape, cast spells which might cause the encounter to go down a path the DM wants to avoid. However, in this case, the issue isn't the feat but the DM trying to force a specific narrative outcome and trying to work around a character ability that makes it more difficult.

aren't you already in combat when surprised?

[bid]

aren't you already in combat when surprised?
I think he meant "break out of the DM shackles."

But, what's your point?

[Grey Watcher]

I think part of the issue is differing answers to "does that first attack happen within initiative order or does initiative get rolled in response to that first (attempted) blow?"

If it's the former, than an Alert character who beats the attacker on initiative does indeed have the full range if options available to them. Character knowledge factors into the decision (for example, they have no idea what direction the danger is coming from, so they wouldn't know where to run to or away from), but they otherwise can do whatever: Dodge action, buff spells, or just swing blindly and hope for the best. ("I attack the darkness!")

If it's the latter, Alert just means they have access to their reactions for that first attack and are immune to any special effects for surprised targets, like an Assassin's auto-crit.

I think I've seen the latter in play more often (if memory serves, a certain famous voice actor DM does it that way). But the former is, I think, RAI?

Basically, I think you'd be well within your rights as a DM to pick either interpretation and just go with that consistently.

[NNescio]

I think part of the issue is differing answers to "does that first attack happen within initiative order or does initiative get rolled in response to that first (attempted) blow?"

If it's the former, than an Alert character who beats the attacker on initiative does indeed have the full range if options available to them. Character knowledge factors into the decision (for example, they have no idea what direction the danger is coming from, so they wouldn't know where to run to or away from), but they otherwise can do whatever: Dodge action, buff spells, or just swing blindly and hope for the best. ("I attack the darkness!")

If it's the latter, Alert just means they have access to their reactions for that first attack and are immune to any special effects for surprised targets, like an Assassin's auto-crit.

I think I've seen the latter in play more often (if memory serves, a certain famous voice actor DM does it that way). But the former is, I think, RAI?

Basically, I think you'd be well within your rights as a DM to pick either interpretation and just go with that consistently.

Former is both RAW and RAI. The latter can be... an acceptable substitute if nobody has Alert or (relevant) reactions. The latter 'simplification' also worked better for 3.X games (because there's an actual separate surprise round), and I believe Mercer was a Pathfinder player/DM, so...

It is, however, definitely against RAW in 5e, clarified to not be RAI by several dev tweets, and will (unreasonably, IMHO) nerf player options like the Alert feat and reactions if houseruled in. It makes playing a (low-level) Wizard much more dangerous, for example.

[NaughtyTiger]

I think he meant "break out of the DM shackles."

But, what's your point?

Keravath made a comment that seemed contradictory (that means it seemed wrong). That isn't common with him.

So my point in asking him about the contradiction is to get him to clarify his comment.

Did that answer your question?

[Contrast]

Does anyone have any other ideas on how to handle this? Aside from banning Alert?

Just to say if you're going to ban Alert you're also going to have to ban level 7+ barbarians.

As others have mentioned if you roll well on Initiative you'll often just be spending that action dodging if the enemy is still hidden - but thats still better than nothing.

[Keravath]

Keravath made a comment that seemed contradictory (that means it seemed wrong). That isn't common with him.

So my point in asking him about the contradiction is to get him to clarify his comment.

Did that answer your question?

Yep :) .. not as clear as I would have liked.

Some DMs like to use a surprise with overwhelming force with initiative in combat as a plot device to force the players to surrender, by having combat start it feels like the characters have a choice when the DM intends that they have no reasonable choice but to surrender. When surrounded the players can then use the first round to say ... "We give up" ... since they can't take any actions anyway. Everyone then moves peacefully on to whatever cut scene the DM had in mind.

(By the way, this is usually not a good way for a DM to structure an encounter, there are better ways to run an encounter where the players won't be given a choice)

However, a character with the Alert feat can take an action in the first round of combat that makes the DMs planned plot device of a peaceful surrender unfeasible which is what I meant by the Alert character causing "combat to break out." which is badly phrased since mechanically combat has already started. In this case, depending on the layout, an alert spellcaster could drop a fireball where they think the opponents might be either making a surrender impossible or making it possible for the party to win the encounter which the DM planned for them to lose.

It is unfortunately somewhat common for DMs to incorporate events like these as plot devices since they are fairly common in literature or in other media where the party gets captured.

[NaughtyTiger]

Yep :) .. not as clear as I would have liked.

Some DMs like to use a surprise with overwhelming force with initiative in combat as a plot device to force the players to surrender, by having combat start it feels like the characters have a choice when the DM intends that they have no reasonable choice but to surrender. When surrounded the players can then use the first round to say ... "We give up" ... since they can't take any actions anyway. Everyone then moves peacefully on to whatever cut scene the DM had in mind.

said this way, then, yeah, i have been guilty of similar. not sure alert would have affected the railroading much...

[KorvinStarmast]

You raised some interesting points that we saw at the table now and again with my alert sorcerer. a year or so ago.

maybe the DM lets you do a free perception check to identify the target for your attack?
1. Perception isn't only sight, it is all senses. If enemy is invisible, the Alert PC's attack is probably at disadvantage.
2. Passive perception may be handy to apply here as a DM.
3. If nothing else the inviso sneaker does not get advantage on Alert PC.
4. Alert PC can do something to shape the battlefield: fog cloud, faerie fire, ball bearings on the floor, guess at target locale and attack, move dancing lights, etc etc etc.

And contrast said this which I did now few times ...

As others have mentioned if you roll well on Initiative you'll often just be spending that action dodging if the enemy is still hidden - but thats still better than nothing. Dodge is a nice damage avoidance thing in certain situations.

In my sorcerer's case, casting mirror image as an action worked one time when I had the initiative and the party was mostly surprised (Fighter rolled a single digit init but was not surprised). There was only one time I recall it working out like that.

I didn't always have the first go, but I was usually one of the first three to go.

[Darkstar952]

3. If nothing else the inviso sneaker does not get advantage on Alert PC.


The invisible person should get advantage regardless, at least for the first attack depending on source of invisibility. That is a basic part of the Invisible condition and has nothing to do with Alert or Surprise.

[Zalabim]

Dodge is a nice damage avoidance thing in certain situations.
Such as when you need to make a dexterity save, or when you are attacked by a creature you can see. Dodge does nothing if you cannot see your attacker (or if your speed is 0.)

The invisible person should get advantage regardless, at least for the first attack depending on source of invisibility. That is a basic part of the Invisible condition and has nothing to do with Alert or Surprise.
In this case, it's a feature of Alert that prevents an unseen creature from getting advantage against the Alert creature. Otherwise, it is the being unseen that normally gives surprise attacks advantage.

[Keltest]

I have a question. If the enemy hasn't attacked or otherwise given any indication of their presence, why are you rolling initiative at all? Combat hasn't started yet. Even if the enemy is tossing a volley of arrows at you from a bunch of bushes or something, there needs to be some sort of hostile action from them to actually initiate the combat, otherwise theyre just spying on you.

[Darkstar952]

In this case, it's a feature of Alert that prevents an unseen creature from getting advantage against the Alert creature. Otherwise, it is the being unseen that normally gives surprise attacks advantage.

Hidden and Invisible are two distinct things, you can be hidden and not invisible, or invisible but not hidden, you can be both or neither.

Alert stops the creature from gaining advantage from being hidden but it will still gain advantage from the Invisible condition.

[Keravath]

Hidden and Invisible are two distinct things, you can be hidden and not invisible, or invisible but not hidden, you can be both or neither.

Alert stops the creature from gaining advantage from being hidden but it will still gain advantage from the Invisible condition.

No. It will not. The Alert text states that it prevents a creature from having advantage on attacks against you due to being unseen by you. Being unseen includes hidden, invisible, in magical darkness when the opponent has devils sight or a warlock shrouded in shadows of moil.

Any condition where they can see you but you can’t see them will not grant advantage if you have the Alert feat.

[Darkstar952]

I have a question. If the enemy hasn't attacked or otherwise given any indication of their presence, why are you rolling initiative at all? Combat hasn't started yet. Even if the enemy is tossing a volley of arrows at you from a bunch of bushes or something, there needs to be some sort of hostile action from them to actually initiate the combat, otherwise theyre just spying on you.

The enemy have declared their intention to attack, as soon as that intention is stated you roll initiative. In normal circumstances their targets are all surprised and regardless of initiative the attackers get the first actual actions in combat.

[Darkstar952]

No. It will not. The Alert text states that it prevents a creature from having advantage on attacks against you due to being unseen by you. Being unseen includes hidden, invisible, in magical darkness when the opponent has devils sight or a warlock shrouded in shadows of moil.

Any condition where they can see you but you can’t see them will not grant advantage if you have the Alert feat.

Apologies you are correct, I see that has been changed in an errata at some point, the original text I was working from states that it negates advantage from hidden enemies. Hidden was changed to Unseen.

This is why I hate errata, it is far too easy to be talking about different versions of the same thing.

[Tanarii]

I think part of the issue is differing answers to "does that first attack happen within initiative order or does initiative get rolled in response to that first (attempted) blow?"Yup. Personally I find the latter works best, and feel that it is the assumption of the system. But that's just my personal feeling on the matter. The important part is:


Basically, I think you'd be well within your rights as a DM to pick either interpretation and just go with that consistently.

[Hail Tempus]

Yup. Personally I find the latter works best, and feel that it is the assumption of the system. But that's just my personal feeling on the matter. The important part is:How do you decide (fairly) who gets to try and make the first blow in combat without rolling initiative?

[greenstone]

Aaron doesn't see the goblin, he just 'knows' that he's about to get attacked. Maybe this spooks the goblin and he slinks away instead of fighting.
Wow, that is a really good point! I'd never thought of it that way.

Aaron only knows "something" is happening. He has no target, so he can't attack but he can take other actions (casting preemptive spells, waking up party members, taking the Dodge action).

[Tanarii]

How do you decide (fairly) who gets to try and make the first blow in combat without rolling initiative?
I don't. We roll initiative to determine that.thats why I said the latter. Althoug rereading the post, maybe that's what was meant by the former. I took the former as being "attack is decided to happen in world first, and no one is revealed until it happens" and the latter to mean "everyone reveals themself by someone starting combat, but the actual attack being resolved happens by rolling initiative".

When someone says they're going to attack, or I determine enemies are attacking, I find out who else is planning on being part of the combat or determine which other enemies are planning on being part of the combat.

Then I determine surprise.

Then I set up the battlefield (if on a battle mst) or describe it (if not) as it is the moment the players or enemies reveal themselves by engaging in combat.

Then we all roll initiative.

Then everyone acts on their turn. This determines who actually attacks first.

Done, and matches RAW. See KorvinStarmast's post for the details.

[Flashkannon]

TECHNICALLY, surprise also gives the attacker advantage, and they wouldn't get that. But, attacking while hidden ALSO gives advantage, so the attacker would most likely have advantage anyway, so again, doesn't actually matter.
Alert also prevents creatures from gaining advantage against you by being hidden from you, so that would be a very relevant difference, especially against any flavor of rogue, as they would lose their sneak attack damage (unless they also had a buddy within 5 feet of the Alert target).