Rule 3.7 Lawyer As Witness

A lawyer generally can't act as a trial lawyer in a case and also be a witness in that same case. The problem is that mixing these two roles confuses things. Juries may have trouble telling whether the lawyer is presenting evidence or arguing as an advocate, and it becomes hard to know when the lawyer is testifying versus making legal arguments.

There are some exceptions to this rule. A lawyer can still handle the case if the testimony is about something nobody disputes, or if it's just about the legal fees charged in the case. A lawyer can also stay on the case if removing them would create a real hardship for the client, if the testimony only covers a minor formality that no one is likely to challenge, or if the judge specifically allows it.

The rule also covers other lawyers in the same law firm. If another lawyer at the firm is likely to testify in a way that could hurt the client's case, the lawyer handling the trial usually can't continue representing that client. This connects to other rules about conflicts of interest, which also block a lawyer from taking a case in certain situations.

Basically, this rule exists to keep trials fair and clear. It stops lawyers from blurring the line between being a witness who gives facts under oath and being an advocate who argues the case, since doing both at once could confuse the jury or create unfair advantages.