To Keep an object from crossing other objects...

[Plangam]

I'm doing my final project, I wanted to make kind of an RPG... You can control a little girl with the keyboard, and she is able to enter some buildings, but then there's that problem I'm dealing with, there's nothing that keeps the girl from going through walls and other characters. And there's even a part in which she's to go through a maze... What would you do?

I like Alice pretty much. I know it's quite basic, but it's the first time in school that we use something like that...

I could create a boolean variable, and place hundreds of invisible objects in rows along the walls. when the girl came too close to any of the objects, or to any of the other characters, the variable would turn to false, and the character wouldn't be able to move any further... That's the best I've come to... Is there not a property to tell Alice to avoid an object from going through another object? As if they really were 'solid'...? Or some other alternative to this...?

Thank you, in advance, of course...