How does a Kill game work?

[Pov]

I'm a reasonably knowledgeable player, but most of my experience comes from online play and home games. I've been considering more casino action lately and I've heard of kill games, but would like to know more about them before possibly finding myself IN one.

So I've picked up that basically while the kill is "on" all the limits are doubled which I guess doesn't really make much difference theoretically other than I may want to buy in for more than usual, but what turns the kill off and on and are there any other rules / adjustments I would need to know?

Thanks in advance.