Scrimmage vest

A lacrosse player wearing a scrimmage vest, the dark blue garment

A scrimmage vest, sometimes referred to as a pinnie or pennie, is a piece of clothing or sportswear, often made of mesh, used in practices as a substitute for a sports team's usual uniform or to differentiate temporary teams in informal scrimmages. Some teams elect to have benched players wear them during a game.

The origin of the term pinnie or pinny is a shortened form of the word pinafore.

An alternative system, especially in less formal situations, is shirts versus skins.