Illegal Moves in Chess
Chess is a fascinating game that people of all ages play around the world. In the magical world of chess, there are some strict rules to follow.
Today, we're going to dive in and find out what makes a chess move illegal, what to do when your opponent makes such a move, the consequences when these things happen in official chess tournaments, and more. Let’s get started!
Here's what you need to know about illegal moves in chess.
- What is an Illegal Move in Chess?
- List of Illegal Moves in Chess
- Difference Between Blunders & Illegal Moves
- What to Do When Your Opponent Makes an Illegal Move?
- What Are the Consequences of Illegal Moves? How Many Illegal Moves Are Allowed in Chess?
- Wrapping Up
- Illegal Chess Moves Infographic
- Illegal Chess Moves Video
What is an Illegal Move in Chess?
An illegal move in the game of chess happens whenever a player violates the official rules, approved and governed by the International Chess Federation (FIDE).
For example, a move that breaks these rules would be placing or leaving your king in check. This is a big no-no because kings don’t like being in check. They can't move into check or stay there. The player should either move out of check, eliminate the piece giving the check, or put another piece between the threatening piece and the king.
Castling is another tricky chess move that can often lead to illegal moves if not done correctly. Don’t worry; we will cover it as well in detail along with a few more, so you will be fully aware of the different illegal chess moves.
List of Illegal Moves in Chess
Illegal King Moves
As mentioned, kings sometimes forget their manners, especially during fast-paced chess tournaments. Here are the main illegal moves for the king:
- Moving the king into check. Kings need their personal space; moving them into check is a royal mistake.
In this position, it would be an illegal move if White's king goes to "h2", as this square is controlled by an opponent's piece - the bishop on "b8".
- Not protecting the king when attacked. If your king is in check, you should defend it, not play with other pieces. Kings don't like to be left alone in a fight.
White won't be able to play Rxb8+ even though it might seem like a great idea. This would be an illegal move since the king needs some rescuing first because it's in trouble.
- Capturing a protected piece with the king. Kings don't play the hero. They can't capture pieces protected by their opponent's army.
In this position, White can't take that sneaky knight on "f2" to dodge the check – it's got a bodyguard pawn on "e3"! That move would be like trying to steal a candy bar with a security guard watching!
Illegal Pawn Moves
Pawns are like straight-shooting cowboys who capture diagonally. They also have a special rule that lets them leap forward two squares at their first move. Moving a pawn two squares when it's not in its initial position is an illegal move.
Here, as the "a3" pawn is not on its starting position (on "a2"), White can only move it to "a4", and going to "a5" would be an illegal move.
Let's revisit the same position. In this case, White can advance two of their pawns by two squares. Can you guess which ones?
If you said the "b2" and "g2" pawns, you're absolutely right! Since they're on their starting squares, they have the option to move forward one or two squares.
In other words, the "b2" pawn can go to either "b3" or "b4", and the "g2" pawn can move to "g3" or "g4." These are all legal moves.
Here, you can see which pawns from White's army have the luxury of choosing whether to advance by one or two squares. Lucky them!
Additionally, capturing in a straight line (instead of diagonally) with a pawn is against the rules.
In this position, White's pawn on "d3" can only capture Black's pawn on "c4" diagonally. Taking the knight on "d4" would be an illegal move and could lead to trouble.
Castling
Castling is a big deal in chess, but it has its own set of rules. Here's how castling can go wrong:
- Castling when your king is in check. Kings can't move their castle when they're under attack.
Trying to castle in this position is a no-no because White's king is in check! Your king won't be pleased with that idea.
- Castling when the king or rook has already moved. Sorry, no dance moves allowed on the board if you want the right to castle.
White's king has already made a move and he won't be able to castle in this game.
- Castling when the king will pass through a checked square (which is controlled by one or several of your opponent's pieces). No shortcuts for kings!
Here's an example to show that castling is a no-go when the king tries to sneak past a square guarded by the opponent's team.
And one more thing – using two hands for castling is a big no-no in the chess world.
Other Illegal Chess Moves
When it comes to official OTB chess tournaments, there are a few other common mistakes.
During a tournament game, you should move the piece you touch first. If you touch your bishop but decide to play with the knight, that's an illegal move.
Another typical mistake is to move a piece with one hand and press the chess clock with the other hand. To follow the rules correctly, players must use the same hand to touch the piece and press the clock.
It will be an illegal move to use one hand for making the moves and the other one to press the chess clock.
Also, remember to use only one hand for all your chess moves, whether it's capturing, castling, or promoting a pawn. Two hands in chess? That's like trying to eat with a fork and a spoon at the same time!
Using two hands for making moves in chess? That's a no-no!
Difference Between Blunders & Illegal Moves
Sometimes you might wonder if blunders and illegal moves are similar. The main difference is that blunders in chess are absolutely legal moves (according to the official rules), but they could lead to an unpleasant and often lost position if your opponent seizes the opportunity.
Illegal moves, on the other hand, are rule-breakers. They're like trying to put a square peg in a round hole.
Let’s take this position for example:
Black has just played 4. ...Ba6.
The player with the Black pieces developed the bishop with 4. …Ba6. In this position, a blunder move by White would be 5.Nxe5.
The player with the White pieces has just committed a serious blunder.
It's a legal move, but it's not very smart, to say the least, and it can get you in trouble. If you opponent seizes the opportunity, you will end up in a worse or even lost position.
On the other hand, in the same position, an illegal move could be if we try to castle short (0-0). This won’t be possible, as the ChessKid website won’t allow us to make this illegal move. The reason is that Black’s bishop on “a6” guards the “a6-f1” diagonal, and as one of the rules of chess states, we can’t castle if the king goes over a square controlled by the opponent.
White will not be possible to castle short (0-0) in this position as Black bishop on "a6" covers the "a6-f1" diagonal.
What to Do When Your Opponent Makes an Illegal Move?
Once you notice your opponent has committed an illegal move, you should call the chess arbiter and claim it. If you're playing with chess clocks, stop the clock and ask for the arbiter. This will save you precious time and keep things fair. Sometimes, the referee is busy with other games, so it might take a bit longer for them to come to your table.
The right move when your opponent makes an illegal move: Call the chess arbiter.
Don't touch any pieces or make any moves as soon as you spot an illegal move. Let your opponent finish their move, then raise your hand just like you're in school.
Taking your opponent's king if it's left in check is another illegal move. It's like two wrongs don't make a right. Call the arbiter and let them sort it out.
What Are the Consequences of Illegal Moves? How Many Illegal Moves Are Allowed in Chess?
The consequences of an illegal move can vary depending on the type of tournament. The arbiter will usually clarify the rules at the start.
Chess, like any game, has specific regulations and rules that must be followed.
In rapid or blitz tournaments, if your opponent makes an illegal move and you call the arbiter to confirm it, you get an extra minute on your clock. That extra minute can be a game-changer, especially when every second counts.
Typically, one illegal move is allowed, but a second one will result in an immediate loss. So, remember to play by the rules and keep the royal game in good shape.
Wrapping Up
Now you know what illegal moves are in chess, how to identify and avoid them, and what to do when your opponent goes wrong. May this knowledge help you avoid making illegal moves and lead you to a path of legal and strategic chess play. Best of luck in your future chess adventures!
Illegal Chess Moves Infographic
Check out this printable below, designed to guide you forward with the topic.
Find more useful Infographics and other chess materials on our Resources page.
Illegal Chess Moves Video
Check out the short video below to learn even more about illegal moves in chess.