Top 5 Illegal Moves Made by Grandmasters (Yes, It Happens!)

When we think of Grandmasters (GMs), we imagine flawless moves, deep calculations, and superhuman precision. But guess what? Even the best slip up sometimes—and yes, even they make illegal moves. Whether it’s time pressure, a lapse in focus, or just a weird brain blip, these moments prove that GMs are human too.

Here are the Top 5 most shocking illegal moves ever made by Grandmasters:

 
🥉 #5: Hikaru Nakamura’s Mouse Slip (Online Blitz)
Game: Online Blitz, Chess.com
Illegal Move: Promoted a pawn to a knight—but the knight magically teleported!
What Happened: In an intense blitz battle, Nakamura accidentally dragged a knight to a square where it couldn’t legally move (due to a pre-move error). He instantly laughed it off, showing his sportsmanship.
Why It’s Memorable: It wasn’t over the board, but it shows how even online GM games aren’t immune to illegal weirdness.

 
🥉 #4: Vladimir Kramnik Misses Check (2008)
Game: Kramnik vs. Deep Fritz, 2006
Illegal Move: Ignored a check and made a calm move as if nothing happened.
What Happened: Against the mighty computer Deep Fritz, Kramnik was in check—but simply didn’t notice. He made a regular move, and only afterward realized the error.
Why It’s Memorable: This wasn’t blitz or bullet—this was a classical game between a World Champion and a computer!

 
🥈 #3: Veselin Topalov’s Double Move (Rapid, 2016)
Game: Topalov vs. Shirov
Illegal Move: Moved two pieces in one turn.
What Happened: In time trouble, Topalov touched two pieces quickly—made one move, then tried to “fix” it mid-turn by moving the second. The arbiter ruled it illegal.
Why It’s Memorable: This is the kind of thing you’d expect at a beginner’s club—not from a former World #1!

 
🥈 #2: Vassily Ivanchuk Ignores the Clock (World Cup, 2013)
Game: Ivanchuk vs. Kramnik
Illegal Move: Forgot to press the clock.
What Happened: Ivanchuk made his move—but didn’t hit the clock. For several seconds, Kramnik sat confused while his own clock kept ticking.
Why It’s Memorable: Chuky is a creative genius but often in his own world. This moment captured that perfectly.

 
🥇 #1: Magnus Carlsen Castles Through Check (Norway Blitz, 2019)
Game: Carlsen vs. Aronian
Illegal Move: Castled through a square attacked by an opponent's piece.
What Happened: Magnus castled kingside, not realizing one of the squares was under attack. It wasn’t noticed until much later—and even the commentators missed it!
Why It’s Memorable: The World Champion making a basic rule error? Legendary. It proves that pressure and speed can catch anyone off guard.

 
Final Thoughts
Even the greatest minds in chess are prone to mistakes. Illegal moves are rare at the top level—but when they happen, they’re unforgettable. Whether it’s nerves, blitz pressure, or just plain oversight, it’s a humbling reminder that chess is as much psychological as it is logical.

Have you ever made an illegal move in a tournament? Let me know in the comments—and don’t worry, you’re in grand company 😉