Nothing can be treated as evidence which is not introduced as such.

Explanation

(English-origin maxim.) Matter not formally introduced into evidence cannot be considered by the tribunal — a party who fails to offer material into the record may not rely upon it, however relevant it may be.

Where this applies

• A juror happens to know a relevant fact about the case from personal experience, but since that knowledge was never introduced as evidence, the jury cannot consider it.
• A lawyer mentions a damaging document during closing argument but never actually entered it into evidence during the trial — the judge instructs the jury to disregard it.
• A party has a devastating recording that would win the case, but her attorney forgot to introduce it during the evidentiary phase — the recording cannot be considered because it's not in the record.