In the circle of miniatures wargaming (specifically Warhammer 40,000) it's a "type" of team-planning and preparation method that involves at least a year's commitment to working on minatures on a grand and hyper-detailed scale. No one player/person can be "bloid". It's a group-think/group-work method. Hive mind if you will.
A massively geeky (albeit skilled) group effort to produce a stunning 'the whole is greater than the sum of the parts' minatures army. Coordinated artistic and creative efforts that go outside the normal requirements (expected and unexpected) of the hobby.
Setting new "requirements" for other teams for the next year's event. Bastards making it hard for everybody else.
Usually used as an exclamation with word "word" - Bloid. Word!
Only by out-bloiding the other teams do you stand a chance of even competing at (said event). They left no expense spared and raised the bar in a typical Bloid fashion. What are you doing? I'm Bloiding.