Non-gambler does not exhibit gambling behavior. Casual gambler gambles on impulse or happenstance. Curiosity and social reasons are motivators. This may be the start of a gambling career or just an unrelated episode for a person who will never gamble on a regular basis. Occasional gambler gambles through a determined act.
Common motivations are escape or a special occasion.
A less common but significant motivation is hope. Professional gambler gambles as part of a studied approach to a game where the element of skill is sufficient to give a player an advantage. The motivation for gambling is economic gain. Problem gambler exhibits the potential for becoming a pathological gambler. The gambling behavior then compromises, disrupts or damages personal, family or work.