Most civil trials require either a unanimous verdict or a specified supermajority, depending on the jurisdiction and type of case. A hung jury happens when jurors genuinely disagree after real deliberation and are unable to reach that required level of agreement.

This is different from a juror simply refusing to deliberate at all, which courts treat as a separate problem and may address through instructions or, in rare cases, replacement with an alternate before deliberations are complete.

Before declaring a mistrial, a judge will often check in with the jury about their progress and may give additional instructions encouraging them to continue deliberating in good faith and to consider each other's viewpoints.

Judges generally have discretion in how long to let deliberations continue and how much encouragement to give before concluding that further deliberation is unlikely to produce a verdict.

Once a judge determines that continued deliberation would not be productive, they will formally declare a mistrial due to the hung jury. This means the case is procedurally unresolved on the deadlocked claims, as if that trial never reached a final verdict.

A mistrial from a hung jury is different from a mistrial declared for other reasons, such as serious procedural error, but the practical effect on the current trial is similar: the matter must be resolved through some other path forward.

The most common path after a hung jury is a retrial in front of a new jury, though parties often use the outcome as an opportunity to reassess the strength of their case and explore settlement instead.

The decision to retry, settle, or in some cases drop the case depends on each party's evaluation of the costs, risks, and likelihood of a different outcome the second time around.