In The Westing Game, the theme of "Lies and Deceit" has a lot in common with the theme of "Identity." Here's why: the majority of lies, tricks, and disguises in this text all have to do with who people say they are and who they're pretending to be. Either they tell a few occasional lies – like Turtle saying she's the bomber to protect Angela – or they tell lies constantly, like Sam Westing pretending to be Sandy, the doorman. There are lies of omission and lies based on deliberate choices; these moments of deceit protect some characters, even as they damage others. Even the person who wins the game has to keep that truth hidden from everyone else.
Although The Westing Game is based on a giant lie – Westing's death – that lie doesn't hurt the characters nearly as much as the bomber does, or as their (sometimes) cruel actions against each other do.
While the mastermind of The Westing Game tries to pass off his lying and deceit as strategy and fair play, that doesn't disguise the fact that his actions hurt people and have real potential for causing harm.