In political science, the initiative is a means by which a petition can force a public vote on a proposed statute, constitutional amendment, charter amendment, or ordinance.

Some well-known examples of initiatives are various ballot measures or propositions enacted by voters in states such as Oregon and California, such as California Proposition 13 (1978), which limited real estate tax rates.

An initiative is distinguished from a referendum in that a referendum is submitted to voters by a vote of a legislature, while an initiative can be placed on the ballot in another way, often by obtaining a sufficient number of signatures on a petition. The availability, if any, of an initiative or referendum process varies from state to state (or political jurisdiction).

See also: recall.

The term is also used in games such as chess. In role playing games such as Dungeons & Dragons, initiative refers to the order in which characters take actions.