For an unfortunate grappler caught in a precarious situation, this simple hand motion can be the difference between consciousness/unconsciousness or having a functioning limb/not having a functioning limb.
Sometimes, a fighter caught in a submission wisely taps out before damage is done, signaling "mercy" to the referee.
Well, begin the slideshow to see what happens when a fighter chooses not to tap.
P.S. Be sure to click the links in the slides!
Tom Lawlor has mastered the art of fashion.
Unfortunately, he hasn't figured out how to tap out properly.
Against Chris Weidman at UFC 139, Lawlor found himself trapped in a tight D'arce choke with no way out.
Rather than tapping out, Lawlor took a little nap on the octagon floor and woke up with one more loss on his record and a No. 10 spot on my list.
Do you see that smug look on Jones' face?
The young light-heavyweight phenom, Jonny "Bones" Jones, earned the right to look a little cocky after his UFC 140 victory over Lyoto "The Dragon" Machida.
After a first round that saw "Bones" look mortal for the first time in his UFC career, the young champ rebounded in the second with a tight guillotine choke that left his foe limp and lifeless as he crashed to the canvas.
Hey Lyoto, you should have tapped.
Shinya Aoki has forged a long career in the sport of mixed martial arts by taking his opponents to the ground and submitting them in spectacular, oftentimes brutal, fashion.
Despite his impressive résumé, not one of Aoki's fancy submissions compares to the hammerlock he pulled off on Mizuto Hirota.
After securing the submission, Aoki cranked and cranked until Hirota's arm gave way.
But the brutality didn't end there.
After the referee stepped in to save Hirota's mangled arm from further damage, Aoki proceeded to taunt his injured opponent and cement his submission as one of the nastiest of all time.
And to think a simple hand motion could've prevented it all...
Demian Maia is one of the best Brazilian Jiu-Jitsu practitioners in MMA history, so when he wraps his limbs around you, you might want to consider tapping the canvas.
Ed Herman didn't get that memo.
Locked in a ground battle at UFC 83, Herman found himself tangled up in a web of legs as Maia secured a tight triangle choke.
Within seconds, Herman was out cold, and UFC fans had a new "craziest submission ever" to talk about.
So for that, thank you for not tapping, Mr. Herman; we appreciate you looking out for us.
I can't even talk about this one.
Just look at this gif and enjoy the mental scarring.
I know I did...
Even though no bones were crushed and no shoulders were torn from their sockets in this finish, Faber's rear-naked choke on Takeya Mizugaki is one of the most disgusting submissions I have ever seen.
Honestly, Mizugaki looked dead, and that is horrifying to see.
Refusing to tap, Mizugaki fell victim to the vice grip of Faber, and the rest is history.
Faber via technical submission (rear-naked choke) for the No. 4 spot on my list.
Can you believe that such an angelic face will gladly rip your arm off?
Neither could Miesha Tate, apparently, as she refused to tap for a solid 15 seconds despite being caught in a vicious armbar.
"The Gracie Hunter" himself, Kazushi Sakuraba certainly lived up to his nickname at PRIDE 10 when he squared off against grappling wizard Renzo Gracie.
Sakuraba secured a tight kimura standing and took Gracie to the ground, forcing the ta—erm, I mean, referee intervention—late in the second round.
Sakurba's win proved once again, you just can't make a Gracie tap (you can annihilate his joints, though).
That win leaves only...
Apparently, Antonio "Minotauro" Nogueira didn't see the film of Frank Mir's submission win over Tim Sylvia.
That, or he never learned how to tap.
Whichever option it may be, Mir's submission win over "Minotauro" at UFC 140 was horrific.
After being rocked by punches, Mir found salvation in the form of a kimura, and he never let go.
Even after the snap, crackle and pop.
With this arm-ripping victory, Mir became not only the first person to KO Nogueira, but also the first man to submit him.
That's good enough for the top spot on my list, wouldn't you say?