Short answer. There are specific requirements. Section 5 requires supporting and opposing affidavits to be made on personal knowledge, to set out facts that would be admissible in evidence, and to affirmatively show the affiant is competent to testify to the matters stated, with certified true copies of any referenced papers attached or served with it.
What the law says
Supporting and opposing affidavits shall be made on personal knowledge, shall set forth such facts as would be admissible in evidence, and shall show affirmatively that the affiant is competent to testify to the matters stated therein. Certified true copies of all papers or parts thereof referred to in the affidavit shall be attached thereto or served therewith.
Rule 35, Section 5 — Form of affidavits and supporting papers. Read the full provision →
Personal knowledge, not belief or hearsay
The affidavit must be made on the affiant's personal knowledge, excluding statements based on what the affiant merely believes, was told, or assumes to be true. This requirement mirrors the personal-knowledge standard that would apply if the affiant were testifying live in open court, since an affidavit supporting summary judgment is meant to function as a substitute for that live testimony.
The evidence-admissibility standard
The facts set forth must be the kind that would themselves be admissible in evidence, meaning an affidavit can't smuggle in facts that would be excluded, for instance as hearsay, if offered directly at trial. A court reviewing the affidavit will disregard any portion that recites inadmissible matter, even if the rest of the affidavit is otherwise properly executed and substantively relevant to the pending motion.
Competency must be shown affirmatively
The affidavit has to show, on its face, that the affiant is competent to testify to the matters stated — not merely assert facts without establishing the basis for knowing them. This usually means explaining how the affiant came to know what they are attesting to, such as their role, position, or direct involvement in the events or records described in the affidavit. An affidavit that simply recites facts without explaining how the affiant came to know them leaves the court unable to assess whether the affiant is actually competent to attest to those matters.
Supporting documents must be attached
Certified true copies of all papers, or relevant parts of papers, referred to in the affidavit must be attached to it or served along with it, so the court and opposing party can verify what the affidavit relies on. An affidavit that references a contract, a receipt, or another document without attaching a certified copy of it falls short of what this section actually requires.
Related provisions
- Rule 35, Section 5 — Form of affidavits and supporting papers
- Rule 35, Section 6 — Affidavits in bad faith