In general, attorney-client privilege in litigation (and administrative or tax procedures) has the effect that a lawyer can refuse to answer particular questions, but if they do not, the evidence from the testimony will be valid, and the lawyer themselves will only face disciplinary liability. In contrast, in a criminal trial, attorney-client privilege is covered by the evidentiary ban, so regardless of the lawyer's will, their testimony cannot be used as evidence. An exception to this is the power of the court to exclude attorney-client privilege, but this is rare and does not apply to defenders of the accused.

All messages, communications, notes and documents concerning the case that were received from the client or other people, regardless of where they are located, are covered by attorney-client privilege.

However, in criminal proceedings the general rule is that evidence cannot be held inadmissible only on the basis than it was obtained illegally or in contrary to the provisions of the Code of Criminal Proceedings.