So I want my character to run when I click a key on the keyboard. For example when I click shift my speed will increase. I tried to use the KeyDown function but it doesn't really work. Is there another way to do this?
The main reason for input scripts not working is that they're local. User input can only be taken from LocalScripts.
However, KeyDown is deprecated. UserInputService is the current way to get user input. http://wiki.roblox.com/?title=API:Class/UserInputService