Short answer. Evidence is admissible when it is relevant to the issue and not excluded by the Constitution, the law, or the Rules. Rule 128, Section 3 sets a two-part test: relevance to the issue at hand, and the absence of any constitutional, statutory, or rules-based exclusion that applies to it.
What the law says
Evidence is admissible when it is relevant to the issue and not excluded by the Constitution, the law or these Rules.
Rule 128, Section 3 — Admissibility of evidence. Read the full provision →
Two conditions, both required
Section 3 sets admissibility as a conjunctive test: the evidence must be relevant to the issue, and it must not be excluded by the Constitution, the law, or the Rules. Meeting only one of these is not enough — evidence that is relevant can still be excluded, and evidence that is not excluded can still fail for lack of relevance. Both conditions have to be checked independently, and failing either one is sufficient by itself to keep the evidence out of the trial record entirely, no matter how strong it is on the other count. Courts apply this test at the point evidence is offered, meaning a party cannot simply present material and expect it considered — admissibility has to be established, on both counts, before the evidence becomes part of the record the court may actually weigh.
Relevance as the first gate
Relevance ties the evidence to the actual issue in the case — it must have a bearing on the fact being contested. Evidence unconnected to any issue the court needs to resolve does not clear this first requirement, regardless of how reliable or interesting it might otherwise be. A party offering evidence has to be ready to show this connection, since relevance is never simply assumed by the court on its own. Evidence about a matter nobody has put in issue in the pleadings, for instance, will typically fail this first gate regardless of how compelling or dramatic it might otherwise appear. The issue itself is fixed by the pleadings and the pre-trial order, so what counts as relevant in one case can be entirely irrelevant in another involving similar facts but a different issue actually joined.
Exclusion as the second gate
Even relevant evidence can be excluded by a specific source of law — the Constitution, a statute, or the Rules of Court itself, such as privileged communications or improperly obtained evidence. Section 3's structure means admissibility always requires checking both gates, not assuming relevance alone settles the question. Common examples include privileged communications, evidence obtained through an illegal search, and hearsay statements, each excluded by a specific, identifiable rule despite whatever relevance the evidence might otherwise carry. Because exclusion has to trace to the Constitution, a statute, or the Rules themselves, a court cannot exclude relevant evidence simply as a matter of discretion or preference — there has to be an identifiable exclusionary source behind the ruling, not just a sense that the evidence is unhelpful or unpersuasive.