All puzzles must be original contributions. Submissions may not be copies of puzzles published elsewhere. If we find that you've copied a puzzle from elsewhere, we will remove it and take action to prevent against further infringement.
Does it apply if it is your own? For example, say I create a puzzle for my blog, can I put it up here as well?
It's highly likely that that's the case, so long as you can prove that the two of you are the same person. I'm pretty sure mathgrant has done this once or twice.