Bounded Accuracy in 5e D&D

[Thorin]

I stumbled across this entirely helpful and informative post about "Bounded Accuracy" in fifth edition, which explains why we don't see runaway attack bonuses and armor classes like we used to in third and fourth editions:

https://www.dandwiki.com/wiki/Understanding_Bounded_Accuracy_(5e_Guideline)

Long read but very informative, at least it was for me.

And apparently we're not supposed to ever be able to get over a 21 AC for our characters...

[Darren Dirt]

"The DM's monster roster expands, never contracts... Since the monsters don't lose the ability to hit the player characters—instead they take out a smaller percentage chunk of the characters' hit points—the DM can continue to increase the number of monsters instead of needing to design or find whole new monsters. Thus, the repertoire of monsters available for DMs to use in an adventure only increases over time, as new monsters become acceptable challenges and old monsters simply need to have their quantity increased."

There ya go. Makes sense!

[Melbosa]

And apparently we're not supposed to ever be able to get over a 21 AC for our characters...

I don't think we were doing it wrong?  And I've seen ACs that high/higher in Critical Role and other Streams.

So makes me wonder what we may have been doing wrong lol

[Thorin]

Well, the highest you could get is magical plate +3 (AC 18 +3 AC from magic), magical shield +3 (AC +2 +3 from magic), magical ring of protection (+1 from magic), for a total of 27 after attuning two very rare and one rare item.

But I was specifically talking about the linked article where they talk about the design philosophy of not being able to exceed AC 21 without magic and why.

It's certainly _much_ harder to get into high AC and that is apparently _on purpose_.  The article also opened my eyes to why 5e feels so different than 4e and 3e where ACs and attack bonuses just skyrocketed as you levelled.  The "treadmill" they refer to in the article.