This is a procedure in some US states, whereby citizens can draw up a petition for a proposed change in the law. It will be placed before voters in a referendum if it gathers enough signatures.

If the change is approved by the voters, it becomes law.

Sometimes, political parties may organise ballot initiatives on controversial issues in an attempt to drive up turnout among their core supporters. For example, in 2004, a number of states held referendums on Republican-initiated ballot initiatives to ban gay marriage.

Ballot initiatives are sometimes referred to as "ballot measures" or "propositions".