This post was intended to serve as a short tip for DMs saying: “Never surprise a 1st level party!” However, as I started to research the topic a little more, I saw that many folk are confused about how surprise works in 5e.
I’ll be honest and say that – after messing up the Ready action for several years – I could probably do with revising this topic myself!
So let’s go through this, with a fine-tooth comb, and get it down to perfection.
Obviously, our reference for the rules will be the Player’s Handbook (p.189) which states:
What the Rules Say
A band of adventurers sneaks up on a bandit camp, springing from the trees to attack them. A gelatinous cube glides down a dungeon passage, unnoticed by the adventurers until the cube engulfs one of them. In these situations, one side of the battle gains Surprise over the other.
The DM determines who might be surprised. If neither side tries to be stealthy, they automatically notice each other. Otherwise, the DM compares the Dexterity (Stealth) checks of anyone hiding with the passive Wisdom (Perception) score of each creature on the opposing side. Any character or monster that doesn’t notice a threat is surprised at the start of the encounter.
If you’re surprised, you can’t move or take an action on your first 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.
Following this section is a “Combat Step by Step” box out, which states that “Determine Surprise” is the first step of combat (followed by 2. Establish Positions and 3. Roll Initiative).
Ok, so doesn’t look too tricky. Let’s examine the wording more closely. The first thing that jumps out is that one side needs to be actively trying to be stealthy. Generally you’re only stealthy when you know an enemy’s whereabouts, and when they don’t know yours. So we can extrapolate that surprise is something that happens during a planned raid or ambush.
Ambushers Roll (NOT the Ambushed)
Within the context of these rules, the ambushers are very much the protagonists, and its they that roll their Stealth, to determine success, versus their targets’ passive Perception. Note that the victims of the ambush don’t make any rolls (in the case of NPCs ambushing PCs, you may want to change this, to give the PCs more agency… however this can be problematic. See Causes of Confusion below! Also, the ambush targets should be entitled to a Perception roll if actively keeping watch, see below as well).
Spot One (Threat), Spot All
After that, the phrase: “any character or monster that doesn’t notice a threat is surprised at the start of the encounter,” clearly means that if a potential target spots even one of the would-be stealthy enemies then they are not surprised. In other words, every single one of the ambushing team must beat a target’s passive Perception for that particular creature to be surprised. Although the rules also make clear that if one ambush target isn’t surprised, their colleagues still can be, a circumstance most likely to happen if some of them have lower passive Perceptions than their teammates.
You Can’t Be Partially Surprised
One thing we can clear up straight away is that: you are either surprised or you’re not. You can’t be surprised by some creatures, and not by others. If you notice ‘a threat’ you’re not surprised, hence ALL the ambushers having to beat your passive Perception for you to be surprised.
This means that, in practice, you’re only likely to get surprised if a) you have a low passive Perception and b) you’re attacked by a small number of stealthy creatures, who all roll well. (Similarly, a larger group of players will find it very hard to stage a surprise, because one bad roll alerts the target to ‘a threat’, negating any surprise, no matter how high the stealthy party members roll. The number of monsters they are trying to surprise doesn’t affect their chances, assuming those monsters all have the same passive Perception and they are not specifically keeping watch… see below).
Think of Surprise As a Condition
Once you’ve determined who is surprised and who is not, like many 5e players, I find it handy to think of ‘surprised’ as a condition. If you are surprised you are basically ‘incapacitated’ (you can’t take actions or reactions), with speed 0, until the end of your turn in the first round of combat.
‘Sneaking Up On’ vs. ‘Laying in Wait’
I think one area where the surprise rules let us down a bit is that they don’t draw a distinction between sneaking up on someone (very tricky!) and lying in wait, having scouted a hiding place etc. (much easier!). I would give ambushers who are lying in wait either advantage on their Stealth check, OR I would let them default to their passive Stealth score (10 + their Stealth modifier) if they roll badly. Or both!
However, I’d argue that if a would-be target does manage to notice a creature lying in wait, they are likely to have time to warn their teammates about the threat they’ve spotted… let’s pick this thread up in ‘Causes of Confusion’.
Do You Get Advantage to Hit Surprised Creatures?
“Does surprise give advantage in 5e?” is a common question I’ve seen fielded by new DMs. The answer is no… and sometimes yes. The fact that your target is ‘surprised’ doesn’t confer advantage on your attack rolls, but the fact that you are an ‘unseen attacker’ does, if and when that’s the case. Page 195 of the Player’s Handbook states:
When a creature can’t see you, you have advantage on attack rolls against it. If you are hidden–both unseen and unheard–when you make an attack, you give away your location when the attack hits or misses.
From this quote, we can also ascertain that you can only ever gain advantage on your first attack of the combat, as after that you’re considered to have given away your position (and would need to successfully take the Hide action, before being counted as a unseen attacker once more).
Whereas an archer hidden in the woods can clearly claim the benefits of being unseen when attacking a surprised opponent, there’s a bit of confusion over whether a melee attacker can benefit as well. Given that there’s no hard and fast facing rules in 5th edition, it’s sometimes hard to judge if a creature can sneak up on their target or not. Ultimately, it’s up to the DM to decide if the attacker managed to get into melee range of their victim without being seen or not. Usually that will be unlikely, but if the attacker is coming out of thick forest directly onto a narrow path etc. etc. it’s far from impossible. You could also rule that if the ambusher beats the surprised creature’s passive Perception by 5, with their Stealth check, then they get close enough to get advantage on their first attack.
Causes of Confusion
So what causes the confusion surrounding surprise in 5th edition? Well, now that we’re in 2021 and 7 years into 5e, we can probably discount ‘edition fatigue’ and the implementing of an entire ‘surprise round’ that took place in earlier versions of Dungeons & Dragons.
I think, in the case where NPCs/monsters are attempting to surprise the party, a lot of the confusion is down to the fact that DMs are wont to let the players roll a Perception check, making them feel like the active party. Once a player has succeeded on such a check (and one of them invariably will, with 4 or so players rolling) they will naturally tell the DM that they warn their buddies, and suddenly the ambush is a busted flush. This all stems from letting the PCs roll (instead of using their passive Perception), and from them expecting to be able to react to their successful roll, but that’s not how the rules work as written.
Step one of combat, “Determine Surprise”, effectively happens in the very moment the ambush is sprung, after which it can affect each ‘ambushee’ differently, depending on how high their passive Perception is. I think it’s ok – and even fun – to replace the players’ passive Perception with a roll, but, when you do so, just remember that those being ambushed are not the protagonists of the situation, and they can’t react to their roll if they spot the ambushers. The best each player can hope for is to not be surprised themselves.
That’s actually something I hadn’t thought of before but, as we’ve just seen, the rules adjudicate surprise in such a way that success or failure on the ambushers’ Stealth check ALWAYS happens in the very moment the ambush is sprung. That’s far from being realistic, and brings me back to the difference I outlined earlier between “sneaking up on” and “laying in wait for”.
In my imagination, if you spy someone lying in wait for you behind a rock (note, as discussed, you don’t spot them, so much as they fail to hide from you – fluffing their Stealth check vs. your passive Perception), perhaps catching a glint of sunlight reflecting off their spearpoint as you head into the valley, then a) the creature who failed to hide from you is unlikely to know you’ve spotted them and therefore b) you would have plenty of time to warn your mates of the impending attack.
So, I’d continue to distinguish between these two situations – “sneaking up on” vs. “laying in wait for” when adjudicating surprise. As mentioned, I’d make it easier for those laying in wait to ace their Stealth checks, but, if they still fail to beat the passive Perception of all of the ‘ambushees’, then I’d probably allow for the observant targets to warn their allies. Something that isn’t allowed for in RAW, it seems.
For the “sneaking up on” scenario, given how hard it is to pull off anyway, I think we can apply the letter of the law and generously assume that the ambushers are able to get as close to their targets as the cover of the terrain allows, before rolling Stealth in the “Determine Surprise” stage of combat. Of course, if one of them rolls a 1 or fails by 5/10 etc., the DM might decide that they’ve been spotted at a range of 100 feet instead of 10 feet, giving the ambush targets more time to prepare for the ensuing combat.
Passive Perception & Keeping Watch
A good understanding of passive Perception is required to run surprise correctly, and the best way to think of passive Perception is as a radar that’s always on – at least while you’re conscious. This effectively makes your passive Perception the bottom floor of how perceptive you are while awake. If you have a passive Perception score of 15, you spot everything that requires a DC 15 Perception check to spot, no roll required. (Many DMs don’t play the game like this, because it’s rather dull – a character with a high passive Perception tends to automatically spot every trap and hidden passage, taking a lot of fun out of proceedings. But them are the rules!).
The next thing to consider are the benefits of actively keeping an eye out for danger. When you keep watch, you get to contest the Stealth checks of any threats sneaking up on you with an active Perception check (allowing for the possibility that you roll higher than your passive Perception… if you don’t you default to your passive Perception).
This of course raises the question of whether players can claim they are alert and on the watch for danger at all times and get the benefit of an active Perception check at all times. You might rule that players that wish to be actively be alert for danger are effectively taking the Search action repeatedly, and can only travel at half pace for example.
Meanwhile, it’s worth remembering that in RAW (see p.182 of the Player’s Handbook) players travelling at a fast pace suffer a -5 penalty to their passive Perception scores, and shouldn’t be able to persuade DMs that they are actively on the look out for danger!
Remember Light (or Lack of it!)
In total darkness, creatures without darkvision have zero chance of ‘seeing’ an attacker sneak up on them, while in dim light they have disadvantage on any active Perception checks that rely on sight and -5 on their passive Perception score.
And while sight is no doubt the most useful sense in detecting an ambusher, I think we can assume that senses such as hearing, and potentially smell, offer a ‘blind’ watch(wo)man a chance at least of detecting an enemy. Therefore, I would rule that a player or creature without darkvision, in the darkness, has disadvantage and -2 on their Perception checks and -7 on their passive Perception.
Obviously creatures with darkvision don’t suffer any penalties to Perception checks in dim light, and they can treat darkness as others treat dim light. But only to a range of 60 feet, usually.
As we can see, the cover of darkness makes pulling off an ambush much more feasible.
Reversing the Check
The more I think about these rules, the more sense it would make to reverse the agency of the check when a group of monsters try to surprise the party. As it stands, the DM either stops narrating the game to start conspicuously rolling a number Stealth checks, alerting the players to the fact that they are about to be surprised, or they announce the surprise: “Suddenly a pack of savage six-limbed apes swing down from the jungle vines!” and then cumbersomely stop play to perform the required rolls. Neither option is great. You could pre-roll, but I hate doing that (the temptation to fudge the rolls is too great!).
However, if you use the passive Stealth check of the monsters (ie. 10 + their Stealth modifier), then you can introduce the drama (“Suddenly a pack of savage six-limbed apes swing down from the jungle vines”) and have each player roll an active Perception check to see if they’re surprised or not.
This is faster (the dice rolling is delegated) and more fun, and has the bonus that you will actually be able to surprise the party occasionally, as when you roll an active Stealth check for each monster it only takes one average to bad roll to ensure that none of the party are surprised (experienced players rarely build PCs without at least 12 passive Perception!); but a more reliable passive Stealth check should create a DC for the players that will ensure one or two are stung by the ambush. Which is more dramatic.
You could subtract 1 from the monsters’ passive Stealth score for each creature above one that is involved in the ambush, to represent the fact that a larger group is easier to spot. Eg. four girallons attempt to surprise the players… normally these apes would have a passive Stealth of 15, but because there are three extra of them, they have a group passive Stealth of 12, and anyone who rolls under that on their active Perception check is surprised.
Meanwhile, to make it a bit easier for players to ambush monsters, take a look at my group check house rule.
Wow, that was a long post… I’ll try to sum up some takeaways:
- In RAW, surprise is determined in the moment combat begins with the ambushers as the protagonists (rolling Stealth against their targets’ passive Perception).
- The rules don’t deal so well with staged ambushes, where the attackers lie in wait.
- The DM might have to adjudicate at what range surprise is determined, depending on terrain (as this is not covered in the rules).
- It’s really hard to surprise people in RAW, and almost impossible with bigger groups.
- Darkness can play a big factor, and in fact might provide the only scenario where surprising foes is realistic.
- It could be more fun and effective to reverse the agency of the Stealth vs. Perception checks, so that the players are always the agents and so the monsters can benefit from a more reliable passive Stealth check.
Never Surprise a 1st Level Party!
And finally, to the original point of my article…. never surprise a 1st level party! It occurred to me when playing recently that a surprise attack on players that average about 10 hit points is a really bad idea. A character that is surprised and rolls a lower initiative check than the monsters could face two rounds of attacks before being able to act. That’s likely be enough for them to die without taking an action, and that usually makes for a pretty shit encounter.