When is a 'Deadly' Encounter Too Deadly?

[Cheesegear]

Easy example; Four Level 4s, a 'Deadly' encounter is rated at 2000+ XP.

A Wyvern is 2300xp. A Young Red Dragon, 5900xp and obviously an Ancient Red will mop the floor. All of these encounters are Deadly.

What's the upper limit from a Deadly encounter killing a player on purpose, to a DM killing the entire party by accident?

[Lupine]

That really depends on the group and the monster. Some groups can get mopped by a hard encounter, while other groups can clean out multiple deadly encounters easily.

In general, my rule is that the players have little to no chance when the monster’s unadjusted xp is greater than the deadly threshold.
However, when the party is fighting a single large creature, My rule of thumb is that you should calculate the thresholds as if the whole party were one level higher than they are now.

So, to answer your examples, the party would probably not tpk from the wyvern, but either of the dragons is likely to tpk the party. A group of lvl 4s might stand a chance against the young dragon, assuming they plan well, and are able to use their abilities to their max.

[Man_Over_Game]

Simply put, have no attacks that can kill an average Wizard in a single, slightly-above-average hit.

They use the same kind of determination in the books, using the statblock of a...troll or ogre or something as an example of a creature who's CR was bumped because of their expected ability to kill a squishy without interaction, rather than the totals of the entire monster block. I forget where I read that, but it was in response to questions on how they implement CR that isn't consistent with the rules they gave us to do the same. Also, their total DPR shouldn't ever exceed half of the players' combined HP.

Long story short, if your biggest monster can't kill the weakest player in a single turn, you're probably fine.

Swarms are another story. My suggestion is that if you aren't sure if it is too much or not, telegraph it. Swarms die easily if the players can expect them.

[Cheesegear]

So, to answer your examples, the party would probably not tpk from the wyvern, but either of the dragons is likely to tpk the party. A group of lvl 4s might stand a chance against the young dragon, assuming they plan well, and are able to use their abilities to their max.

I mean, the idea wasn't about single targets. I just used them as examples 'cause I don't have to do maths like I would for multiple monsters.

Two CR3s would make 2100xp, three CR2s would make 2700xp - that's more than a Wyvern! Both of these would also be Deadly.


Long story short, if your monsters can't kill the weakest player in a single creature's turn, you're probably fine.

Kill? Or drop to 0?

[Man_Over_Game]

Whichever. I'd say Drop to 0, but you can probably go a little bit beyond that.

That being said, you can do this by dividing actions into Legendary Actions. This allows you to output the same amount of DPR without bursting a player before the team can react to it.

Player interactivity requires players the allowance to respond to a problem, and that can't happen if there is no window to respond.

That being said, dropping someone to 10% HP is fair game.

[Cheesegear]

That being said, dropping someone to 10% HP is fair game.

An Ettin makes two attacks, for 4d8+10 damage. What if I roll high damage by accident? What if I roll a crit? There are some things I don't control (I don't use a DM Screen).

Speaking of Ettins...
An Ettin is CR4, worth 1100xp. Cake.
Xanathar's says a CR4 is worth four Level 4s and terrifying on its own.
Uh?

[Man_Over_Game]

An Ettin makes two attacks, for 4d8+10 damage. What if I roll high damage by accident? What if I roll a crit? There are some things I don't control (I don't use a DM Screen).

Speaking of Ettins...
An Ettin is CR4, worth 1100xp. Cake.
Xanathar's says a CR4 is worth four Level 4s and terrifying on its own.
Uh?


Still fine. Sometimes players get unlucky, and that happens in many levels of play. Not all of your players are that squishy, either.

As long as you limit the damage as "per turn" and not "per round" or "per attack" you're fine.

[Biffoniacus_Furiou]

An Ettin makes two attacks, for 4d8+10 damage. What if I roll high damage by accident? What if I roll a crit? There are some things I don't control (I don't use a DM Screen).

Speaking of Ettins...
An Ettin is CR4, worth 1100xp. Cake.
Xanathar's says a CR4 is worth four Level 4s and terrifying on its own.
Uh?

So if both its attacks hit (with +7 they often will), the most it can deal without a crit is 42 damage. That's enough to drop any 4th level character that doesn't have resistance to the damage, but how likely will you roll max on 4d8? Average damage for that is 28, which isn't quite enough to drop a d10 class with Con 12, and if that character has Con 14+ even a decent roll may not drop them. Plus ettins are the type of creature to swing on separate targets, so unless only one character has engaged with it, one character isn't taking both attacks and it takes at least three rounds for it to drop someone.

[DevilMcam]

It does really depends on the group and how well they play together. A ridiculously deadly encounter such as a final boss for the arc can reasonably kill one or 2 pf the PC and still be an epic fight

Among the ridiculously deadly encounters I have encountered were :
- a mummy lordand 4 mummies vS 5 lvl 6 PCs (One dead PC, got resurected)
- a hill giant and a dozen of goblins vs 4 lvl 5 PCs (No one died)
- A Hulking crab VS 5 lvl 2 PCs (No one died)
- A Troll VS 4 lvl 2 PCs (One PC died)

Solo Monster tend to go down Really fast, and aren't usually a big threat unless they have some kind of AoE attacks.

Dragons CR can be deceptive in that way because their breath attack are not very close in terms of damage potential.
Reds seems to be the most dangerous, but due to beeing a dex Save that does fire damage, most of the party will only ever take half damage from the breath. while a white dragon Breath will very often deal the full amount.

[MrStabby]

So the short answer is that there is no hard rule based on CR. There are a few reasons...

1) CR in the MM is roughly correlated with danger... but it is a long way from exact.

2) player or character knowledge swings things a lot more than a couple of points of CR on a monster stat block once you get to late Tier 2 and beyond. Knowing you might have better luck throwing Int saves at a dragon for example through to not trying to turn undead on a flesh golem.

3) Not having the right tools can turn a total pushover fight into a nightmare. No ranged attacks vs flying enemies, no sunlight against vampires or very few non-fire spells against demons. The converse is true as well - if the paladin can reliably divine smite undead then the encounter will be a lot safer for the party.

4) The situational bonuses and penalties either side can have will swing a good few points of CR/XP as well. Does the party have any magic items? If so, then deadly probably massively under represents what the party can take on. Other simple things like is the encounter indoors or outdoors, day or night can, depending on access to dark vision, make an even battle a massacre. This is before you even get to ambushes that can leave the party surprised.

5) As a rough rule, PCs can expend resources to turn hard fights into easier fights. Action surge, high level spell slots, hit dice... Things get a lot harder when the PCs dont have resources to spend.

So whilst I would say you can go above deadly without a TPK, if you do it too much you are sooner or later going to find something that isnt stacked in the PCs favour. This is especially true if you have some kind of feedback loop where difficulty increases to the limit of what the players can handle.

Whatever answer fits your players at your table with your level of optimisation and your levels of magic items, it is still always worth thinking through an encounter and thinking about who is likely to have what abilities.

[MaxWilson]

Easy example; Four Level 4s, a 'Deadly' encounter is rated at 2000+ XP.

A Wyvern is 2300xp. A Young Red Dragon, 5900xp and obviously an Ancient Red will mop the floor. All of these encounters are Deadly.

Edit: to answer your first question specifically, Tier 1 parties are more fragile. The Wyvern and the dragons are all potential TPKs, although the wyvern might need to use hit-and-run tactics to do it and would be stymied by spells like Tasha's Hideous Laughter or Web. The dragons could just brute-force a typical level 4 party to death. I'd expect the wyvern to kill or knock out between 0 and 4 PCs in a 4-PC party in a straight-up fight-to-the-death non-hit-and-run fight, and I'd expect the dragons to kill all 4.


What's the upper limit from a Deadly encounter killing a player on purpose, to a DM killing the entire party by accident?
In my experience, once the party hits level 5, if the DM is not deliberately trying to game the encounter construction system with mobs of cheap monsters or monsters that punch above their CR--that is, if the DM is merely selecting monsters based on roleplaying considerations like what monsters make sense to find together, the thresholds look pretty much like:

Deadly: party will win with no difficulty even if they've had multiple other encounters since their last rest.
Deadly x3-4: it's hard to predict who will win if the PCs just wade right in and start fighting. Call it a 50/50 chance for each team. If the PCs do something tactically or strategically clever, or use magic items, they will likely win.
Deadly x5-6: Call it 60/40 in the monsters' favor, if the PCs don't do something clever or use magic items.
Deadly x10: monsters will almost certainly win unless PCs do something clever, but TPK is not as likely as it seems to the DM. This is the point where I would typically look at the players and say something like, "I think you guys are about to die," and yet somehow, sometimes they don't.

This is useful information if you're trying to construct adventure areas that are supposed to be "off limits": a Deadly x12 encounter functions as something like a wall, and ways to bypass that encounter (like a chalice that lets you befriend the Fire Giant leader and bypass the Deadly x20 squad of 6 Fire Giants that he leads) are kind of like doors through these walls (the chalice is in a key to the door). Players can also tunnel under the wall (use stealth to bypass the fire giants, or Detect Thoughts/Suggestion if what the giants are "guarding" is information and not just physical access to an area).

If you as DM are deliberately seeking out overpowered or underpriced monsters and playing them as intelligently as you can, it's possible to TPK/K (Total Party Kill/Knockout) the party at much lower difficulty thresholds. This is useful information e.g. if you want to build one-way doors or "slides" in your adventure or sandbox, e.g. "If the PCs approach the drow citadel, they are likely to encounter a standard patrol of 20 Drow Warriors, who will likely TPK them using stealth tactics if the PCs are below Tier 3 and not super-stealthy themselves or poison-resistant, even though it's technically only a Medium fight. This leads to the 'drow slavery' section of the sandbox where they are Geased to repeatedly fight monsters to the death as gladiators for the drows' amusement, but have the opportunity to participate in or escape during the civil war between House Khadesh and House Toronai after three months and three gladiatorial tournaments."

You can also use one-way slides as ways to introduce friendly NPCs (healers, rescuers).

Now that I think about it I suppose you could also use brute force like a Deadly x12 encounter as a one-way slide, but somehow I've never done that. Maybe it seems cheap. One of the other neat things about using non-Deadly monsters to TPK the party as a one-way slide is that once players eventually learn the tricks of dealing with that type of monster, the one-way slide becomes a two-way door: e.g. if you pre-cast Resist Poison and Pass Without Trace and take time to Hide and Search during combat instead of just Attacking all the time, you can wipe out Drow patrols all day long in stealth-on-stealth duels. (This is just an example--other tactics work too, like Insect Swarm/Fireball spam in the likeliest hiding places.)

[Zuras]

Remember that a “Deadly” encounter only means there is a significant chance of one or more PCs being reduced to 0 HP. Whether this is likely to lead to a TPK or PC fatalities relies more on whether the enemy attacks include AoEs and action denial abilities.

Also note that glass cannon enemies with extremely powerful offense but modest or weak defenses are far more variable in combat. A mind flayer plus a bunch of grimlock mooks can range from a speed bump to a TPK depending on how many PCs get caught in the initial Mind Blast and how their saves go.

As a DM I personally max out somewhere between 3x Deadly and 4x Deadly. Beyond that I feel like the odds are stacked against the PCs and I am too tempted to fudge things in their favor. Not blatantly, but if the combat starts at 3x Deadly odds I’m rolling the recharge die behind the screen and the enemy wizard is more likely to cast Slow or some other debuff that allows counterplay than just spamming Fireball or Cone of Cold.

Others have mentioned range, hit and run tactics, and monster specific weaknesses. I would just simplify that to say that anything 1x Deadly or higher with a monster that has a gimmick can quickly lead to PC deaths if the players don’t have a counter. This could be anything from fighting lycanthropes without silver or magic weapons, trolls without acid or fire, or giant alligators if they can grapple one pc and drag them underwater. The simplest is ranged attackers with a higher move than the PCs.

I am a mostly Combat as Sport DM, so I like to build encounters with trick monsters at a Medium to Hard XP threshold to produce a challenging encounter with a lower risk of taking out more than one PC, but that’s just my personal style (the second time they encounter a trick monster all bets are off, because even in Combat as Sport, it’s learn or die where I’m concerned).

[Demonslayer666]

I attempted to make a chart that has classifications above deadly: quite deadly, very deadly, and extremely deadly.

2 CRs above deadly was the quite deadly range - one or two party members will likely die
3 CRs above that was the very deadly range - half or more of the party will likely die
Anything above that was extremely deadly - you don't stand a chance, the whole party will likely die

Unfortunately, that only works for a solo monsters.

[MaxWilson]

I attempted to make a chart that has classifications above deadly: quite deadly, very deadly, and extremely deadly.

2 CRs above deadly was the quite deadly range - one or two party members will likely die
3 CRs above that was the very deadly range - half or more of the party will likely die
Anything above that was extremely deadly - you don't stand a chance, the whole party will likely die

Unfortunately, that only works for a solo monsters.

This seems like an iffy methodology to me, because 2 or 3 CR doesn't really make THAT much difference. Notice for example how a Young White Dragon (CR 6) and a Young Green Dragon (CR 8) have almost identical stats.

[Drogorn]

This leads to the 'drow slavery' section of the sandbox where they are Geased to repeatedly fight monsters to the death as gladiators for the drows' amusement, but have the opportunity to participate in or escape during the civil war between House Khadesh and House Toronai after three months and three gladiatorial tournaments.

I read this as greased and got some rather amusing ideas.

[MrStabby]

I read this as greased and got some rather amusing ideas.

So it wasn't just me?

The pinguid games campaign.

[5eNeedsDarksun]

One thing that seems to make a significant difference when I'm planning an encounter that includes multiple cannon fodders and one or two more significant foes is how effective the higher CR monsters are from distance. It's one of my complaints with many of of the higher CR Demons among others is that they don't have too many abilities that can be used while they are sacrificing their minions. Just add a few more spells that they can cast from safety and they are good, but if they are just waiting their turn to fight, they don't have a lot of impact.

[Eldariel]

I attempted to make a chart that has classifications above deadly: quite deadly, very deadly, and extremely deadly.

2 CRs above deadly was the quite deadly range - one or two party members will likely die
3 CRs above that was the very deadly range - half or more of the party will likely die
Anything above that was extremely deadly - you don't stand a chance, the whole party will likely die

Unfortunately, that only works for a solo monsters.

For solo monsters, it's incredibly swingy: Wizard lands that one CC effect and the whole encounter might just turn into a cakewalk even though nominally its CR is 10+ points above the party. Like my favourite example: Balor/Pit Fiend vs. a party with a level 7 Diviner. Diviner rolls low for Portent. Suddenly it's just a game of getting the Wizard close enough to cast Banishment and Portent Fail it. Portent bypasses Magic Resistance and their save bonuses (level 7 Diviner is liable to have DC15 spells so a roll of 1 or 2 fails). Similarly the Wizard could Polymorph said fiend and while that wouldn't kill it, it would be enough to remove it as an obstacle for a good while (long enough to "manually imprison it" by digging a deep hole with Mold Earth or some such and casting it down there).

Hell, you could stun/whatever them in their animal forms and autocrit with a level Big Smite [Pally 2/Sorc 5 could Twin Booming Blade smiting with two level 3 slots for 4d8 each; 10d8 + weapon damage if you somehow stun/paralyze the creature - Twinned BB easily suffices to hit it for ~100 damage if one is autocrit] or whatever if you wanted to try actually taking it out (you get two rounds of free attacks after Polymorph; everyone readies an action to attack on the first character's turn after the enemy's turn and then everyone does their normal full round output on it). If you have a Nova-capable party, it's not impossible to even kill them.


One thing that seems to make a significant difference when I'm planning an encounter that includes multiple cannon fodders and one or two more significant foes is how effective the higher CR monsters are from distance. It's one of my complaints with many of of the higher CR Demons among others is that they don't have too many abilities that can be used while they are sacrificing their minions. Just add a few more spells that they can cast from safety and they are good, but if they are just waiting their turn to fight, they don't have a lot of impact.

Yeah, I ultimately just ended up using the fiend SLA blocks from 3e. I felt they were just needlessly gutted making them (particularly devils) little more than beatbots.