A person who devotes a large portion of their time towards gaming and gaming variations. A
hardcore gamer might often attempt to
optimize their playing style, often by the use of gaming gear or mods/addons; this practice is often common for casual gamers, but to some lesser extent.
"A casual gamer is someone who schedules the game around their life, while a hardcore gamer schedules their life around the game." -TotalBiscuit (a.k.a TotalHalibut; The
Cynical Brit)