The chess-oriented definition here doesn't quite tell the whole story. Any player who sacrifices material (i.e., one or more pawns or other pieces) is playing a gambit. The hope is that your opponent will have to expend valuable time capturing the material, allowing you to gain a lead in development or mount an attack. The premise behind gambitry is "nothing ventured, nothing gained."

I find this excellent term poorly used by the general public. Too often, it is used to mean a simple tactic, as in "The candidate's most recent gambit was to appear in front of a high-school crowd." A better use would be "The candidate's most recent gambit was to appear before a trade-union crowd, which may rankle his conservative voting base."