I don't know the exact rules of Ludum Dare, but if possible, I would have sketched out on paper (and if no prepared materials are allowed, memorized the important points) the general structure of the game, so that all I'd be doing during the 48 hours would be the actual programming.
Actually, he didn't do this. Part of the LD is that the theme/topic for the Dare isn't revealed until the game starts. He actually spent about twenty minutes staring at a 5-line text file labelled "ideas," just thinking out loud while he tried to come up with a game type.
That doesn't mean he didn't have a lot of prepared material. For example, when I was in school, I would have an essay planned out days in advance of an english exam, despite not knowing what topics were available until actually sitting the exam. With practice, its possible to bend and twist the given topics so your prepared material fits nicely. I imagine you could do the same with LD - plan the gameplay and art style and how different aspects should be coded in advance and then tweak it to suit the theme/topic once its been announced.
Oh, I see. I thought that the individual contestants came up with their ideas entirely on their own. I suppose this approach makes it much easier to judge, and more competitive as well.
