Generating Random Numbers with Standard Deviation

I'm experimenting with AI for an extremely simple simulation game. The game will contain people (instances of objects with random properties) who have a set amount of money to spend.

I'd like the distribution of "wealth" to be statistically valid. How can I generate a random number (money) which adheres to a standard deviation (e.g. mean:50, standard deviation: 10), whereby a value closer to the mean is more likely to be generated?