Two different forms the mandamus order itself can take, reflecting different procedural stages of the case.

In jurisdictions that preserve the traditional common-law structure of mandamus procedure, courts can issue two different types of writs depending on how far the case has progressed: the alternative writ and the peremptory writ.

The alternative writ

An alternative writ gives the respondent a choice: either perform the requested act immediately, or appear before the court and show cause why the act should not be required. This form functions as an intermediate procedural step, giving the respondent an opportunity to contest the petition before a final order issues.

The peremptory writ

A peremptory writ is the final, unconditional command — an order that the respondent must perform the act, issued after the court has considered the respondent's response (or the respondent's failure to respond at all).

Why this two-step structure exists

This structure reflects mandamus's historical origins as a writ that commanded immediate compliance while still preserving basic due process for the respondent, who is entitled to be heard before a court issues a final, unconditional order.

Modern procedural variation

Many jurisdictions, including the federal system, have streamlined this traditional two-step process into a more conventional civil litigation framework — a complaint, an answer or motion to dismiss, and a final judgment — without formally using the "alternative" and "peremptory" terminology, even though the underlying logic (a chance to respond before a final order issues) remains similar.

Where the traditional terminology still appears

Some state courts, particularly in appellate mandamus practice, continue to use "alternative writ" and "peremptory writ" terminology explicitly in their procedural rules and opinions, so petitioners in those jurisdictions should become familiar with the specific local practice.