Wednesday night's game will feature Neil Patrick Harris, Jane Kaczmarek, and Cheech Marin.
"They're out here playing for their favorite charities," said Trebek. "They have some embarrassing moments, but for the most part it doesn't bother them too much. For them it is OK because it is not their regular job and they can win a lot of money for their charity."
And the ultimate goal of this special celebrity invitational is to raise $1 million. That amount of money can be life changing for a charity.
"When you consider that some of the charities represented by the celebrities are small local charities," said Trebek.
Harris is playing for an L.A. based organization called Food On Foot.
"Jay Goldinger is one amazing guy," said Harris. "He has served meals to the homeless every Sunday since 1996, without fail. So it's a small organization. It is not religious. There is no agenda to it. It is just this guy who just really wants to help these people get a step up on life."
In order for Harris to help his charity he needs to keep his eye on the prize, and his finger on the buzzer.
"I am hoping there are a lot of theatre questions and no geography," said Harris. "I am hoping that there are questions about Muppets and not the Old Testament."
Watch the celebrities put their brain power to work on "Jeopardy" Wednesday at 7 p.m. on ABC7.