I have a stupid question, but I'm trying to move a character using the arrow keys. I know that (thanks to a tut in this forum) key.IsDown() does it in AS2, but how can I do it in AS3?
Sadly no, there is no key.IsDown property in as3. You need to make your own. Basically you set some event listeners that detect when keys get pushed or lifted, you make a Boolean for each key and you turn it on when the player pushes the key and turn it off when he lifts it. I used this tutorial and it works, but he does some... weird things. I would do some google searches before if I were you.