The Alphastream Game Design Blog

Special Reasons Why DMs Have Trouble Challenging Players

A dragon holds a miniature in its jaws as it climbs a stone bridge crossing a river of magma, all created with Dwarven Forge terrain.
I derive great pleasure when my monsters swallow PCs… I admit it!

Many Dungeon Masters have trouble challenging players. As discussed in the first part of this series, part of this may be due to the difference between PC Hit Points and the relatively small damage monsters can inflict.

In the second part of this series I shared the difference between the damage the DMG says a monster should inflict and the actual average damage for published monsters. Published monsters inflict too little damage, so we can add a die of damage to each of their attacks (or two dice for high CRs). In some cases we may even move up the scale of our encounter challenge (for example, to provide an Easy challenge for a strong party, we could use the math of a Medium challenge). Importantly, we aren’t trying to win. Our goal with these techniques is to be able to provide a fun challenge when appropriate. We also don’t want our battles to consistently feel easy. Adding damage is an easy and usually effective way to have fights feel tough even if victory is expected.

However, all of the above can fall apart due to special cases. That’s what we want to look at in this article. You see, all of the DMG’s monster damage values assume a monster is hitting every time. But this is not likely the case.

Macabre Waltz, by Willian Murai, depicts a necromancer (Liliana Vess) dancing with a zombie.
Macabre Waltz, by Willian Murai

Do Your Post Mortems

A DM can learn a lot by acting like a mortician (or a necromancer). After an encounter ends, take a look at the factors influencing the feel of the challenge. I say feel, because awesome combats often feel challenging (but may not actually be that hard) and lame fights often feel boring (offering little of interest despite monsters that have an awesome concept).

Here are some common factors and what to do about them.

Armor Class

DM: “Oh, sweet! That’s a hit against a 23 AC! I finally hit you!
Player: “Shield!”
DM: “Sigh.”

In the DMG, 5E’s monster construction rules for damage assume the monster is hitting every round. That assumption is based on expectations around bounded accuracy, a design principle that generally keeps ACs from reaching absurd levels and (in most cases) allows creatures to have a reasonable chance to hit each other.

Unfortunately, some PC builds can practically guarantee never begin hit. Between armor, shield, and the shield or similar spells/features, some PCs will be hit a few times per adventure instead of once per round. The builds aren’t even that hard to pull off. And even a moderate amount of optimization into AC can be destabilizing for play.

While you can increase all monster attack bonuses, I find it’s better to talk to your players as far back as a session zero for your campaign. Encourage players to show restraint so the game works well. If one character really wants to be an impossible-to-hit tank, work it out so they are the only such PC and have the monsters play off of that. You might add an extra monster just for that character to lock down, for example. You can also increase your use of non-attack damage, such as through traps, saving throw effects and spells, fields or auras of auto-damaging fire or acid, and the like. Don’t make every skeleton a skeleton with a flaming aura – but adding such events periodically will keep a tank’s life interesting.

Strategically, as DM you don’t have to play the tank’s game. It’s fun to do so to reward the tank. But for a challenge, smart monsters focus on targets they can damage. Give your monsters mobility or position them so the tank can’t tie them all up.


I’m a player at the Winter Fantasy convention. All the other players at my table know each other. The DM sets the scene, with an aboleth and its minions emerging from a pool. I’m excited, as I’ve never fought a 5E aboleth. The wizard diviner goes first, casts banishment, and sets the DC for the aboleth so it fails. The aboleth never acts. We win easily.

Next room is similar, this time with hypnotic pattern so none of the monsters can attack us. No PC takes damage.

I say, “What if next time we let the monsters act and see what they can do? What if we only cast our big spells if it’s hard?” They all laugh. We finish the adventure an hour early, and the players seem bored.

Some of the most problematic spells are those that deny or cancel actions. Banishment, counterspell, hypnotic pattern. These and similar spells prevent monsters from doing what they are intended to accomplish. Having that happen from time to time is awesome – the game intends for players to be awesome and shine! Having it happen all the time is not intended and typically not much fun for the DM. But I also think it isn’t that fun for players in the long run. It can be hard to grasp, but when every monster is easy, the excitement slowly drains away from play.

Action denial, especially when monsters are removed from play, is a huge game-changer. An aboleth and 5 CR2 underlings is a Deadly challenge for five level 10 PCs (16,300 XP). But if they cast banishment on the aboleth, it becomes an easy challenge (4,500 XP). That’s a huge 12k XP swing! (And, the same is true if we go back and look at a high-AC character and have the big monster only attack that PC… we are essentially removing those two characters from play and the rest of the encounter is an easy challenge for the remaining PCs.)

Some spells are problematic in certain situations. It’s hard to challenge players with an encounter focusing on poison or fear if the party has cast heroes’ feast. Magical darkness is very problematic when combined with a party that can always see in magical darkness. Constant temporary hit points, especially coupled with upcast aid spells are more subtle but still unbalancing because the already low damage from monsters is now incapable of providing a threat.

My favorite way to resolve these situations is to talk to players. It won’t matter if I add extra dice of damage to the aboleth if it will always be banished. We have to create a table culture of the players using tricks appropriately. This is especially true at high levels.

From a design perspective, you can lessen the impact of action-denying spells by concealing the biggest threats in your fight. If the party encounters just the minions at first, they might cast hypnotic pattern on them, and that’s when the aboleth appears. And maybe your important monster has a special feature to allow it to succeed on saves, or to otherwise resolve likely situations. It’s okay to protect your special bosses so the challenge can prevail (though you do want to reward your players most of the time for their reasonable tactics).


Summoning Spells are a special consideration, because they do two things. First, they add firepower. The damage output over time from all the monsters summoned by a typical spell in the PHB is significant and can often exceed that of a fireball of the same spell level. However, that’s not all. The summoning also provides action denial, because the sheer number of summoned monsters prevents foes from easily moving around most battlefields. The monsters are forced to fight the summoned creatures. The math of a monster’s damage is not meant to work with the math of monster hit points. The result is that a DM’s monsters would need many rounds to defeat just the summoned monsters. Defeating PCs and summon monsters is practically impossible. (And we haven’t even addressed summoning pixies that can cast polymorph to become T-Rexes.)

The simplest tactic is to focus fire on the summoner, because they are concentration spells. But that isn’t very rewarding for the player. The best option is for summoners to only use the summoning spells and features in Tasha’s and later books, since those summon a single creature. The spells are still strong, but they aren’t as problematic.


This is generally a mild issue, but some players try to use familiars and similar companions as a means to grant combat advantage each and every round. 5E’s design intent is that gaining advantage should in most cases require an action. That’s why the cantrip true strike works the way it does (and why almost no one casts it). If you are getting advantage every single round… it’s probably not meant to work that way.

DMs can talk to players, but I find that the problem goes away when I require a mini or token for all familiars, and especially when my monsters telegraph their intent. “The ogre takes a look at your familiar. It’s clear that the ogre is considering attacking it.” And, don’t forget those area of effect spells. Once you take these factors into account, players either become more conservative or we see a lot of dying familiars.  

Dwarven Forge terrain is used to create bottlenecks and pressure the characters with dangerous traps.
Between a rock and a spiky place!

Battle Lines

Many fights have a linchpin foe. This is the creature that is the key to the challenge. In the earlier example, it was the aboleth. Less obviously, a fight might have a monster that has capabilities that lock down PCs, deploys important conditions, or has AoE or strong damage that will keep the battle challenging. There may also be monsters that are glass cannons. They dish out important damage, but can be quickly defeated.

When you conduct your post-mortems, and when you set up your next encounters, think about how the battle will play out and how PCs and monsters will use the space to their advantage. It’s a very different battle with goblins if some goblins with ranged weapons are up on ledges that are hard to climb. It’s a very different battle when the enemy spellcaster is outside the range of counterspell and if they start combat with full cover (or are otherwise hidden) from the fighter.

Practice makes perfect. Play with your terrain and learn how different setups impact the challenge. A bridge PCs must cross to get to the goblins who have a ballista. An obvious trap between PCs and the big bad. Cover benefitting some foes. An NPC in peril, slowly descending into a pit full of something nasty. Shape the environment so the encounter is not simple. (If there is enough interest, I could share some advice on this topic in a future article.)


A key limiting factor is that as a DM we have a single brain. Our players outnumber us, usually 3-6 brains against our one. And, not every DM is tactically-minded. If you aren’t, you may need to adjust your damage or your encounter challenge level further to make up for that.

And, you may benefit from the amazing advice in The Monsters Know What They’re Doing, a web site and books by Keith Ammann. Keith breaks down individual monsters so you can look them up before the game and know how to run them well. This is particularly useful for complex monsters and monsters that cast spells – he breaks down those actions and spells to recommend the most useful and impactful ones so the monsters shine against the players. His advice also captures the flavor of the monsters, helping you lean into their design and communicate that during play. Highly recommended!


In a conversation with Brazilian author and cartographer Christian Zeuch, he shared the story of a recent fight with several zombie girallons.  Girallons (CR4) are actually tough creatures, dealing more damage than expected. A zombie girallon (CR3) deals the same damage and may get back up when reduced to 0 hit points! So, why was it easy for the players? Breaking it down, he recalled that the monsters appeared in waves. A PC used hypnotic pattern. Other waves were similarly handled. The PCs ended up basically unhurt. And that’s where the post mortem can be useful. Waves are a great technique to use… but they make battles easier and more manageable for the PCs.

The number of fights in a day is important. Many features have a maximum number of times they can be used. Recent subclass design ties the daily use of features to the proficiency bonus (2 at 1st level, 3 at 5th level, 4 at 9th level, 5 at 13th level, 6 at 17th level). Spell slots tend to be numerous, with the real limit being on the caster’s most powerful spells. This all means that having just one or two fights per day practically guarantees that the party will unleash their full potential. It can take a small dungeon or lair to work through those features and you realistically may not be able to work through all the uses when they count.

As a result, the WotC staff say that they design under the assumption that a party is fully prepared. I encourage DMs to do the same. This is especially important if the party has problematic features. For example, the cleric of the twilight domain or the artificer with the temporary hit point cannon will likely impact every battle. Thus, you have to mitigate and resolve any problematic issues because they will realistically be problems almost all the time. Talk to your players!  

Thomas Christy is an expert DM who often streams his games. He often adjusts the challenge level on big fights. In a recent run of a level 15 adventure he essentially doubled the damage of the big bad (you can watch the video to see how it ended up fun).

Picture of a tweet by Thomas Christy, where he says he doubled monster damage.

Engaging Story

Of all the special considerations and techniques, this is the most important. An engaging story and compelling scene will be fun for you and your players regardless of how hard the combat is. A room with four goblins is boring, even if the goblins deal heavy damage. A room with four goblins on the other side of a pit, building a clockwork flamethrower? Even if the party defeats the goblins easily, the potential energy in that situation will capture their attention and lead to fun play. You can read more about potential energy and engaging design in this series.

Wrapping Up

Adding damage helps greatly. It compensates for the way monsters are designed and the high hit points of most PCs. Even if the players win easily, damage is something players recognize. When a monster finally hits a high AC character and doesn’t deal much damage… it comes across as boring. If the damage is high, the player feels excitement and validation for their build even if they were only hit once. They can feel like the battle would have been tough if they hadn’t been so clever!

But damage can’t solve every problem. As DMs, conducting post-mortems helps us to constantly improve the scenes we provide so they can be more challenging when appropriate. The more we understand what the party is doing, the better we can make adjustments or more clearly speak with our players about potential issues. The game is always a social contract between people who want to have fun together, so have that conversation if that’s the best solution.

What factors have an impact in your games? Which ones have you had success or trouble mitigating? Let us know below.

One comment on “Special Reasons Why DMs Have Trouble Challenging Players

  1. James
    October 19, 2023

    The way I’ve found around high AC is spells. One of my games is high-level and high-magic and therefore high-AC. But spells requiring Constitution saves will hit the rogue and monk, and Dexterity saves will hit the paladin and druid, and Wisdom saves will hit them all. (I often joke that Wisdom should be capped at 15 because if you were really wise you’d stay home, but this particular group is exceptionally unwise.) When I pick a monster with spellcasting, I have no problem changing their spell list to optimize for save attacks. (I also take Banishment out of the monster’s spell list, because I did that to a PC once and the player had nothing to do the whole battle and I’ll never do that again.)

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This entry was posted on June 23, 2021 by and tagged , , .


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