D&D 5E Drawbacks to Increasing Monster AC Across the Board?

[Andvari]

I like lower to hit and fewer HP as it makes combat faster and feel more dangerous due to less time spend updating HPs and more risk from a “lucky” streak.

Unfortunately I wouldn’t want to mess with it in an existing system like 5E as it affects other things. Damage spells that bypass AC become more potent, for example.

 

[Tonguez]

I think its more fun to give monsters things like evasion and repositioning abilities or use cover and hide and terrain advantages, make combats dynamic - use lair actions for everything

 

[Uni-the-Unicorn!]

So, our group recently got to play several sessions of D&D 5E over the past few weekends. More than we've gotten to play consistently in quite some time, so that is good. Lots of fun.

However, one of the players has noted that it's very easy to hit the monsters. It seems a lot easier than previous editions, especially easier than AD&D.

By my calculations, between the minimum +2 proficiency bonus every character gets along with usually at least a +2 ability score bonus on the attack roll along with some other things, it seems like it's probably 20% to 30% more easy to hit an average AC than it was in 1E at low level.

Now, don't get me wrong. I really like 5E and am definitely not wanting to start any sort of edition war. However, I'm wondering if it might hurt to increase the monsters' armor classes by a few points in general and how far I could go in that regard without the ACs ending up too high when our group gets some characters to high level? Would a four point bump in monster AC be too much? I'm pretty sure two points would help, but not sure about going the full 4 points (or even 5 or 6) as it would likely break bounded accuracy and make high level monsters too invulnerable to lower level groups.

Has anyone done this? What were the results?

5e was designed to have a 65% bit rate which is indeed higher than many earlier editions. And a complicating factor is that rate is accurate only if you don’t give the PCs magic weapons. So, if you give the PCs magic weapons, and you want to have the same hit rate, then you do need to increase th monster AC to match.

 

[pnewman]

If you only raise monster AC's, but not monster Save DC's (which are also pretty low) you will benefit fighter type monsters more than caster type monsters. Unless that is an intentional choice, you may want to think about raising their save DC's too.

I just started a 2025 only Greyhawk campaign, and I am giving all the monsters +1 to ht and +1 to their Save DC's but leaving their AC's as is. I want the fights to be a little more hazardous, but I do not want them to be even more slow and grindy, and I think that raising monster AC's would do that.

 

[ezo]

Back to this stuff again...

I am in the rare camp of lowering monster HP and increasing AC. As it is, in 5E you might as well get rid of the attack roll and just roll damage. While the 65% rate concept is nice, it should be the peak, not the base. Because as it is, the peak is closer to 85-90% IME. At that point, "hitting" is boring and missing becomes the fun part IMO.

I don't want the slog to continue, which increasing AC would do, but by lowering monster HP that counters that issue. While 35% is certainly too low for some people, I think a base around 45-50, with a peak around 65% is best personally.

 

[^Dagon^]

The biggest drawback is longer combats.

For martials if we look at 5E compared to 1E it is easier to hit enemies at low level in 5E and harder to hit them at high level in 5E.

In 1E high level Fighters hit most enemies on a 2. In 5E it is usually around 4 or 5 IME.

If you are looking at non-martials, they hit easier in 5E at all levels I think.

They do take longer indeed and this was a plus in my games. Longer combats, more tactics (if you have players that like such things). When I say longer I mean more rounds but they do not take really long in time because I run combats very fast. Each participant has 10 seconds to decide his action, else he loses his turn and that holds true for the DM too. I am not talking about performing the action, just deciding on it. This time limit makes combats much more alive.

 

[Lakesidefantasy]

It's wild to see so many different experiences at different tables.

After decades of playing Dungeons and Dragons with my friends, I moved far away and had to find a new gaming group. In the process I discovered that my way of playing Dungeons and Dragons was not the same way everybody played. Hell, it wasn't even the most common way. (For example, I was shocked to meet so many people planning a character's development from level 1 to level 20. )

 

[Horwath]

Back to this stuff again...

I am in the rare camp of lowering monster HP and increasing AC. As it is, in 5E you might as well get rid of the attack roll and just roll damage. While the 65% rate concept is nice, it should be the peak, not the base. Because as it is, the peak is closer to 85-90% IME. At that point, "hitting" is boring and missing becomes the fun part IMO.

I don't want the slog to continue, which increasing AC would do, but by lowering monster HP that counters that issue. While 35% is certainly too low for some people, I think a base around 45-50, with a peak around 65% is best personally.

problem is that high attack roll is not rewarded, except a crit, so we have that the roll of 7-19 is completely the same and we just hope for a "20"

there could be degrees of success for extra damage or "mini-crits" for better rolls.
beat AC by 5, +50% damage
beat AC by 10, +100% damage
beat AC by 15, +150% damage
beat AC by 20, +200% damage

roll a "nat 20", extra +50% damage

graze mastery:
miss AC by 5 or less: deal only 50% damage.

then when you need "8" for successful attack, there is a reward for rolling 8, more for rolling 13, even more for rolling 18, and normal extra for rolling 20.

 

[tetrasodium]

I suspect that the 65%hitrate in 5e was on some level helped along by bad math and hst came from approaching the attack chain as a thing where later attacks depended on the previous one succeeding rather than each attack being an isolated 65%.

If that were the case iit would be a maybe reasonable chain of 65%>42%>27%>17% before buffs & magic items rather than 65%>65%>65%>65% before buffs and magic items bring it to near certain success each attack

 

[ezo]

problem is that high attack roll is not rewarded

But this isn't a problem. As the saying goes, it is a feature, not a bug. The hit is the reward. The damage determines how well the attack actually hits. Rolling higher on the attack just means you are more likely to hit. In this respect the nat 1 always miss nat 20 always hit is fine.

except a crit, so we have that the roll of 7-19 is completely the same and we just hope for a "20"

Correct. The attack roll is binary. You hit or you miss. It really is (and should be) that simple. I have never even been a fan of the critical hit on natural 20 and so have for a long time now moved to critical damage.

The nat 20 makes no sense for critical hits, frankly speaking. In AD&D days when we began using them the caveat was a 20 is critical if you hit with a 16 or lower. If you only hit with 19 or 20, having half your hits be critical is nonsense IMO.

there could be degrees of success for extra damage or "mini-crits" for better rolls.
beat AC by 5, +50% damage
beat AC by 10, +100% damage
beat AC by 15, +150% damage
beat AC by 20, +200% damage

roll a "nat 20", extra +50% damage

This is too convoluted for my tastes but I can appreciate the design.

graze mastery:
miss AC by 5 or less: deal only 50% damage.

Nope. You miss, you miss. Period. Not my thing but hey have at it for your game.

then when you need "8" for successful attack, there is a reward for rolling 8, more for rolling 13, even more for rolling 18, and normal extra for rolling 20.

The reward is you hit. Isn't that enough???