Hello,
I have been having a few lucid dreams a night as of late, but my problem is changing things in my dream. I am unable to make things change or anything of the like. The closest I have come to any thing of the sort is in one dream before I became fully lucid I was able to change a house in the dream into another house of another dream I just had.

Last night I was trying to get away from these people, but some string got caught on a fence and knotted. I knew I was dreaming so I tried to will the string to come undone, but it would not.

And for another example: In two past dreams after I became lucid; I felt I was going to be getting into some kind of trouble when I left my room, so I tried to produce a sword to fight with if I had to. But as hard as I tried to will it (the sword) into existence in my hand it was not there.

My question is: is it just dream control I need to change things? And if so can you gine me a few pointers that have worked for you int he past? Or do I need to imagination the changes as I am willing them to happen?