'This is a Unix system!'

Jakob Nielsen’s clearly in the holiday spirit, since his latest Alertbox is an exposé of the 10 biggest User Interface bloopers in films, which we’ll all see countless times over the next few weeks.

I’d forgotten all about Jurassic Park, where a 12-year-old girl saves the day and stops the usual rampaging dinosaur hordes through her knowledge of Unix. Gripping stuff, I'm sure you'll agree. However, there is one Jakob missed: noughts and crosses as an allegory for Mutually Assured Destruction. WarGames, of course.

Admit it, you’ve seen it. But, if your memory isn’t so fresh, WarGames sees teenage hacker David (Matthew Broderick) poking around WOPR, your typical global nuclear defence mainframe. Sadly, sloppy information architecture (seen above) causes poor David to inadvertently trigger global thermonuclear war – although, in WOPR’s defence, it does at least offer a confirmation dialog.

Realising his rather egregious error, David quickly stabs away at Ctrl-Z, but WOPR is having none of it. He can’t even shut it down through Task Manager. In the end, he has to rely on a cunning hack. By forcing the computer to play noughts and crosses against itself repeatedly, David causes WOPR to realise (in a flash of logic that somehow drains electricity from surrounding appliances) that the Nash equilibrium for global thermonuclear war is to not start it. WOPR smugly declares “the only winning move is not to play” and cancels the missile strike.

A close call indeed. And that, kids, is what happens when you don’t do user testing.