10 Things You Didn't Know About Jumanji

Part of the reason Joe Johnston didn't want Robin Williams for Jumanji was because of the actors reputation for going off script. According to legend, the director did not want any thing, or rather anyone, detracting from the film, which is why someone like Tom Hanks was a much safer choice.

Despite his doubts, Johnston would end up having to work with Williams anyway, but this did not waylay his fears over the actor improvising instead of sticking to the script, because when you have a personality on set as big as Robin Williams then it is inevitable he will find a way to make the role truly his own.

Resigned to the casting choice, Johnston decided that the easiest way forward for all involved would be to allow Williams the chance to improvise whole scenes, just as long as the actor then agreed to shoot the scene as it was written by screenwriters Jonathan Hensleigh, Greg Taylor and Jim Strain.

This meant shooting a lot of scenes twice, which was not cheap but maintained a harmonious atmosphere on set.