In piam memoriam fundatricis nostrae

I know what I'm getting Fin for zir birthday. It's a DVD of a film that was never released in the US. So it's only available as a British DVD. I thought some of you might know about this.
We can play DVDs on the DVD player in our house, but it's never been used to play anything but American DVDs. I need to do something to it to make it play British ones, right? Is there even a minimal risk of bollocksing it up in so doing?
Also, I can theoretically play DVDs on the (Linux) laptop. Is region encoding a problem there?