There exist perhaps hundreds of different bridge moves and conventions, each with a different name and method to learn.

There are enough in the world that I would imagine there is no single bridge player who knows all of them at once – even though seasoned bridgeurs might know many.

Some of the moves, however, are known as completely illegal.

There aren’t all that many illegal moves in bridge, but it’s fair to say there are a few. Learn them, or you might miss them when they happen (or accidentally fall into the well yourself).

Here are 5 illegal bridge moves (& what they mean).

1. An insufficient (or impossible) bid

A bridge bid can never be lower in value than what the previous player has bid. Within bridge, this is as set as the rules of gravity and the laws of nature.

The same, it’s a complete impossibility to bid higher than 7NT. The number doesn’t exist. That doesn’t mean someone won’t call it out at your next club game – and that’s what the Tournament Director is there for.

At online games, it’s easier. The options you can’t click to bid are automatically eliminated from the bidding tab, so you can’t make any mistakes!

2. Illegal signals

An illegal signal is anything that passes between opponents or partners to give clues about the game, play, bidding, or hand.

It could be a crack, a cough, or a sentence. Anything that serves as a hint, cue, or answer to your partner that is not in the form of a bridge bid counts as an illegal signal.

Illegal signals can even be passed around online.

Do you think you’ve seen the presence of an illegal signal during a bridge game?

Report it to your relevant club, anti-cheating commission, or to Bridge Base Online. Ideally, have concrete proof instead of just mild suspicion.

3. Unauthorized information

Unauthorized information (also called UI) is different to an illegal signal, but similar in many ways.

The definition of UI might be a little broader. Instead of describing an illegal signal during game, UI means the forwarding of any details relating to the game, the hand, or the play that might affect it.

Obviously, it’s an illegal bridge move – and it’s the kind that gets you issued with a ban in the majority of bridge clubs online or not.

4. The alcatraz coup

The Alcatraz Coup is rare, but one a bridge player might eventually hear about or see during a game.

It’s one thing to gain the upper-hand during play, though never using this particular move.

One clue that the move isn’t a desired one is the fact that it’s named after Alcatraz, the infamous prison. That’s bad enough, don’t you imagine?

5. The Chicago convention

The Chicago convention sometimes gets called “tongue-in-cheek” by bridge resources, but it’s no laughing matter when it’s used to cheat a game (and the players don’t know to recognize it).

When players pick up their cards, the keyword is a sentence or question containing the term “Chicago”.

For example, “Hey, when last did we have a drink at the Alibi in Chicago?”

This tips off the participant’s partner, but usually not their oblivious opponents, to how they’re planning to play. The specific meaning of “Chicago” to the partnership who uses it gets discussed in advance. Hence, an illegal move.