Not a steam achievement, but...

My dad was playing Munch's Oddysee many years ago. In that game, you get instructions at the start of each level from a spirit standing inside two rings of rocks on the ground. If you need instructions again, the game tells you to stand in the outer ring and push the action button. My dad, who isn't the most skilled controller handler, got the game to say something i had never heard.

He stood in the inner ring of rocks and pushed the action button. The game literally yelled at him, THE OUTER RING STUPID, STAND IN THE OUTER RING."

Good times.

https://www.youtube.com/watch?v=OqX__5hGrjo

Software Inc. Apparently people don't like it when you take away their company car, vacation pay, end of year bonus, and end of year pay increase. Who knew.

Spiral Knights. What's cool is I didn't even realize I was in the running for this when I got it.

Something from a Cities Skylines DLC nobody played.

All of my 0.01ish% rarity cheevos are largely easy af things from DLCs or content updates of (somewhat) popular games that were released when most people had already moved on from these games

The really fucking hard stuff is usually around 0.5-3% (CoD BO3 zombies cheevos are insanely common for how hard they are)

Game: Crypt of the Necrodancer

Achievement name: Doppelgänger

Description: Kill a miniboss while possessing one of the same kind as Chaunter (SYNCHRONY DLC required)

You can find your rarest achievement by going to Steam, clicking your profile, edit profile, manage showcase, rarest achievements.

I’m pretty sure I was one of the only people in the world to get Super Hexagon’s final achievement. It was either .01% or .1%. I can’t remember.

Edit: I got to a computer and I no longer have that distinction, a full 6% of people have managed to get it in the past ten years.

All but one of my 20 rarest achievements are from the game Barony. The game has ruined my rarest achievements showcase lol. 16 of them are at 0.1%, the others are 0.2%.

I have bunch of 2% achievements listed on my profile with the "Rarest Achievement Showcase". I feel like they are not even worth mentioning here, compared to the 0.2% lists in this thread. Amazing achievements. I don't know any other way to find the rarest (without involving any third party service).

Is there an easy way to tell, I don't pay attention to those usually

I don't remember what I did to get this, but apparently it involved eating corn. The game was Backseat Drivers.

The most rare ones I have are for delisted games like Marvel Heroes or Rocksmith. So here's the next and more worthy two that were actually a challenge. Both are from Cave Story.

Guacamelee! Gold Edition

Not great, but kinda niche since Super Turbo Championship Edition is the newer version. I played this a lot more on my PS Vita way back when, got the Platinum trophy for it.

One of those dumb Forza Horizon missions where it's not really difficult, just rare because you need to something very specific with a very specific car.

Armello is a board game in which you move into enemy characters to attack them, and the character River can attack someone and deal one damage to them before starting combat.

Getting this required waiting to draw a teleport card, and be able to target it in range of a cluster of three enemies all at one health already (or retain enough damaging cards to bring them to one) before attacking all three.

Apparently some Forza5 achievements in some unpopular gamemode that nobody really bothered with. And some rare Anno2205 ones which may or may not have been unlocked legitimately. All around 0.3%.

In Red Orchestra I have a melee kill with the binoculars:

A Sight For Sore Eyes Gain a melee kill with the binoculars

And in World of Tanks I have Kolobanovs medal.

I don't really remember it, but it doesn't look that difficult..

0,1% Achievement of a very niche game

Rarest is some challenge from the Hunter game that I guess no one else played.

Third rarest is the "Harder" challenge from SuperHot VR.

No achievement but today I'm poised to reach deep on night 5 in elden ring night reign. Apparently only 3% of players make it there.

LASO Master in Halo MCC and Faster in SUPERHOT VR. That and a handful of other ones are listed at 0.5%.

Yes, Chef (Cook 100 Meals) ; Moonstone Island

0.4% of players.

Not my proudest.

My entire rare achievement showcase on steam is northgard and songs of conquest achievements. 0.1% for about 6 of them.

If the order is more granular that the pop up displays, Stoat master is the actual rarest.

Not sure why, it's a good clan!