Chaotic Good

Discovery works both ways. If you want to present an alibi defense at trial, you have to provide the prosecutor with information about that alibi. Defendants have to provide a list of witnesses they intend to call, and the prosecutor may depose those witnesses beforehand. There are certain exceptions - for example, if a prosecution witness lies on the stand, the defense may call a witness not on the list to rebut that witness's statements and impugn their credibility.

Basically, neither the prosecution nor the defense are allowed a "hole card". The "hand" is played open.