Your rarest steam achievement.

Beyond Epic in Shadow of Mordor - 0.21%

According to friend, Unturned has one slightly grindy while not that hard 0.18% achievement for getting all skills maxed, if you're bored :)

Not so fast... from Shank 2 - 1.6%

Nation Red - Boss Obliterator - 0,23%

Torchlight II:
Butterfly ~ Have 50 friends
0.37% of players have this

Well that was easy. :U

greece fire - from civilization V - only 0,3% people have it

Son of Odin for Mount and Blade: Warband.

0.78% of players.

i think mine is: Rats and Ashes - Dishonored (i think its from some DLC) 0.6%

map one from tl2, only like .3% or something

Civilization V: Standing like a Stone Wall: 0,72°%

Bioshock Infinite
Blue Ribbon Champ - 0.49%

The Mighty Quest For Epic Loot

Auntie Social
Get 10 friends in your network
0,6%

I guess mine would be Recon-Qualifikation V with 1.1% from Ghost Recon Phantoms.

But I don't know a better way to find out. I just clicked this single game and looked at it.

Mine is "Hidden and Dangerous " in Sniper elite 3. Only 2.0 % people have it according to steam

Waylaid in "100% Orange Juice", obtained by 0.2%

"It's a trap!" for Tropico 4, 0.86% of players have achieved this one.

Mine appears to be the Master Miner achievement from Spiral Knights. It says only 0,1% of players got that one O.o

Tigranes Magnus from TW: rome II, 0,34

Super House of Dead Ninja's "High Scoring Ninja" achievement, with only 0.37% of players having it..

Not bad, but it has two achievements even harder to get and rarer still. I aim to unlock them, for it is my favourite game on Steam.

Zombie Slayer from Goat Simulator, apparently only 0.4% of players have it

Pathfinder 0.84 (ets 2)

There doesn't seem to be a simple way to find this out.

my rarest achievement is from Metro 2033 Wheeler-Dealer only 2% of players have this

One Finger Death Punch: Score 2000 Kills in No Luca No Survival Mode - 0.48%