How to keep my posters on the wall?

I have many gaming posters on my walls and I keep them on using glue tacks. But some of these posters are falling down BUT some of them are perfectly fine and never falls. So what should I do? Double side tapes are out of the question because I might replace my posters with newer ones and the tapes are peeling my walls' paints off. So any tips or something else to use or how to use the glue tack properly so they won't fall off again?