Short answer. You may ask about any non-privileged matter relevant to the subject of the pending action, which explicitly includes matters relating to the claim or defense of any other party — not just your own — as well as the existence and location of relevant documents and witnesses connected to the whole case.
What the law says
the deponent may be examined regarding any matter, not privileged, which is relevant to the subject of the pending action, whether relating to the claim or defense of any other party, including the existence, description, nature, custody, condition, and location of any books, documents, or other tangible things and the identity and location of persons having knowledge of relevant facts.
Rule 23, Section 2 — Scope of examination. Read the full provision →
The general scope of examination
The deponent generally may be examined regarding any matter, not privileged, which is relevant to the subject of the pending action as a whole. Two clear limits frame this overall scope: the matter in question must not be privileged, and it must genuinely be relevant to the subject of the pending action — but within those two limits, the actual scope of permitted questioning remains quite broad in ordinary litigation practice.
Not limited to your own side's claim
The rule specifically and expressly clarifies that this same scope of examination covers matters relating to the claim or defense of any other party in the case, not just the deposing party's own particular position. A deponent can therefore properly be questioned about the strengths, weaknesses, or underlying basis of an opposing party's own claim or defense, as long as that particular line of inquiry remains relevant to the pending action overall.
Documents and tangible things
The scope explicitly includes the existence, description, nature, custody, condition, and location of any books, documents, or other tangible things connected to the case. A deposition can therefore properly be used not just to obtain a witness's own personal account of events, but also to actively map out what physical or documentary evidence genuinely exists somewhere and precisely where it can actually be found.
People with relevant knowledge
The scope of examination also reaches the identity and location of other persons having knowledge of relevant facts connected to the case. This further allows a party to use a deposition as a tool to identify additional potential witnesses connected to the case, and not merely to gather the particular deponent's own personal testimony about what they themselves personally witnessed or know.
What the scope does not reach
This breadth still stops at the two conditions the rule sets: privileged matter, such as attorney-client communications, stays off limits regardless of how relevant it might otherwise be, and a line of questioning genuinely disconnected from the subject of the pending action does not qualify simply because the deponent happens to know something about it. A party who objects that a question exceeds this scope bears the burden of showing the matter is privileged or irrelevant, since the rule's default is broad access, not narrow permission.
Related provisions
- Rule 23, Section 2 — Scope of examination
- Rule 23, Section 1 — Depositions pending action, when may be taken
- Rule 23, Section 3 — Examination and cross