I was watching an interview regarding the release of “Mordenkainen Presents: Monsters of the Multiverse” in which Todd Kenreck and Jeremy Crawford were discussing why they made the monsters tougher in the upcoming release. According to WOTC‘s research it would seem that the problem with the CR system, in part at least, is the DM not playing the monsters in the most optimal way. I disagree.

My first experience with the CR system not working was when I ran my first home game combat encounter pretty soon after 5E was released. My fifth level players were spying on two Frost Giants (CR 12) when they decided to attack. At the time I assumed I had designed a very difficult encounter but I knew some of the player’s were pretty good at optimization so I thought I’d be in bounds. Two of the players managed to kill one of the Frost Giants in the surprise round. The second Frost Giant was quickly dispatched and the players pulled back to rest. Lesson learned I figured.

But I hadn’t learned the lesson. More encounters were ran. The CR system and any presumption of encounter balance were thrown out and try as a I might I just couldn’t give the players the white-knuckle experience I was looking for. Fast forward to the release of “Out of the Abyss” and I found that stat blocks for the Demon Lords laughable. I ran that campaign at my FLGS for a group of fairly inexperienced players so I ran the stat blocks straight all of the way through. The only demon that gave my party anything like a hard time was Yeenoghu. Yeenoghu had a lot of attacks.

More time passed. More encounters were ran. A pattern emerged. The Dungeon Master’s Guide says parties can handle six to eight encounters a day which is probably true. But I’ve yet to see a party take on more than an average of four and they prefer fewer if they can manage it. Most parties seem to optimize around dumping their most powerful abilities in a fight and then taking a short rest to recharge what they can. They rinse and repeat until their resources get too low it’s long rest time.

Assuming typical adventuring conditions and average luck, most adventuring parties can handle about six to eight medium or hard encounters in a day. DMG, page 84

Given the optimization around rests to recover abilities one solution is to just up the difficulty level of encounters when you know the encounter will wind up being singular or one of very few in that adventuring day. Last Sunday I ran a CR 18 encounter against my party of six seventh level characters. They won, handily. It would have gone much differently had I been able to get the monsters into position but the players locked them down in a Wall of Fire using Evards Black Tentacles and the dice just went against the monsters.

The other option available to the DM is to keep pressure on the players in some way that would require them to take on more encounters in an adventuring day. Perhaps the DM can deploy deadlines, hostages, or make the party actively hunted. But such tactics can only be deployed a few times before the players figure out how to defeat them or just grow tired of a game that’s kept artificially tense.

In a normal game the players can manage where and when they fight fairly well. That’s not a bad thing. But it does make challenging them difficult.

After years of testing CR on various groups I do think it’s fairly accurate at low levels but the system breaks down as you increase party size, party level and player experience. I’ve been playing since 1985 and I can honestly say that monster difficulty has always broken down as the player’s gain experience and magic. There are many factors to consider outside of just how tough the monsters are.

Consider an encounter with a column of one hundred Hobgoblins which according to Fantasy Grounds is a CR 13 encounter. Does anyone really believe that one hundred Hobgoblins marching down a road at a party with a Wizard and a Warlock who can pop-off a couple of Fireballs in a surprise round is going to challenge a party the same as an encounter in a narrow hallway with a Beholder? (Also CR 13) Imagine the same one hundred Hobgoblins marching on a party with no spell casting. CR is at best an approximation but the DM has to account for other factors like party composition, amount of magical items, preparedness (i.e. does the party know what they’re walking into), current available resources, terrain and I’m sure other things I’m missing at the moment.

Ultimately the DM needs to know the monsters and their party and how to challenge the party on their terms which is more art than science. To Mr. Crawford’s point I certainly haven’t always played the monsters in the best way. Sometimes that’s a conscious choice given the circumstances of the encounter. Other times I just don’t want to spend the time getting to know the best possible way to play a monster that will last for a single encounter. With a little more than seven years of playing 5E I can honestly say the fault with the CR system is not sub-optimal play. But don’t mistake that as my attempt to shift the blame for the CR system’s failure back to WOTC. I just don’t expect the publisher of a game as complex as D&D to be able to provide a single formula for encounter design that will work for all encounters and all games.