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

[Hrothgar Rannúlfr]

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?

 

[Awesome Adam]

Everything has lower ACs, but more hit points.

It's more fun for players to hit something and do some damage, than to whiff over and over again. 20-30% more fun.

 

[Rhenny]

During the playtest, I had to adjust numbers like this..giving all monsters +2 to attack and then boosting AC a bit.

Adding to AC will just make creatures more durable so the feel of the encounter will change. Some people may enjoy that. For DMs, the one thing to realize is if each foe has a few more AC points, combats might last a little longer in groups that are melee heavy. So far, I've found that not much will break BA, but higher AC opponents can be much more dangerous for lower/mid level parties that rely on melee more to overcome their foes.

Personally, I don't like using billions of monsters often. I like small, skirmish type battles that have fewer foes. For me, adding to both monster attack and AC works when I want to use less monsters yet still challenge the party. But...I also don't really even use the CR values and XP values to make encounters. I'm much more concerned with what "feels" right for the encounter rather than what is balanced.

 

[Ralif Redhammer]

I have not done so, though there have been boss monsters that I've given better armor. Based on the results, I would not do an overall AC bump. Making things harder now and then is fine, and it can be good to shake things up, say, with a goblin that is a real challenge, but unrelenting difficulty becomes a drag (unless you're playing the Dark Souls series...).

 

[Warmaster Horus]

Just give monsters higher-than-average HP.

 

[Xeviat]

PCs are balanced with low hp and high AC; monsters are the other way around. Glancing at the CR calculator, you may be able to boost AC by 2, but then I'd suggest taking away some HP (15? 30? Hard to say).

 

[Sunseeker]

Just give monsters higher-than-average HP.

This is what 4E did. And you know what people called 4e combat? A slog. And it was, I love the edition but holy heck everything is just a bucket of hit points!

While it may be more fun to hit something and deal damage, on the same note, there's no challenge in dealing damage, it's automatic. Hitting something poses a challenge, using positioning, spells, class features, etc... to boost your attack to be able to hit. But then again, this also depends on the group.

If your group is a bunch of old-school min-maxers like mine who always have at least a +4 to hit on their best ability score, then don't be afraid to up the ante. They've raised the bar, so it's only fair.

Personally, given my group I raise AC by about 2 points across the board and I lower HP by about 25% across the board. It evens out, I think but is more enjoyable to my group because they see the foes as a greater challenge.

 

[abirdcall]

I think it works for the most part. As has been noted, whiffing over and over again is frustrating for people.

People tend to have stats that are too high but it doesn't sound like that is a problem for your game. The archery fighting style giving +2 to hit is a slight design flaw, I think it should be either +2 DMG or ignore partial cover.

If you increase ACs will you also increase saving throws?

 

[JeffB]

This is one of the things I love about 5e and (to slightly lesser extent 4e) PCs dish it out, but they take it too.

I'm an unashamed disciple of the LBBs and MCM, but the abundance of "I miss ", is not something I miss.

 

[FormerlyHemlock]

Biggest impact of bumping ACs across the board is that you'll have to rewrite the MM. If you bump it by +4 however you can just increase everything's CR by one without recomputing, since +4 to AC is always equal to +1 CR. If you leave CR unadjusted you'll be buffing summoning spells considerably.

Other impacts: Sharpshooter/GWM will become less valuable, and fighters in general will be less competitive with wizards (since saving throw spells will be stronger). PCs may feel a bit cheated if they need magical plate armor to have the same AC as a bog-standard goblin.

I wouldn't recommend tweaking numbers this way for the sake of tweaking numbers--it's generally contrary to the whole point of Bounded Accuracy, which is "the numbers mean something." If you want to give all your goblins splint mail and shields (AC 19), do so, but don't give them AC 19 instead of AC 15 just because you want them to be harder.