Board Thread:Off Topic/@comment-25396609-20150517000450/@comment-24993958-20150531135558

When someone throws an object and has it return to his/her hand by pointedly ignoring the laws of physiques or by ricocheting off several walls, with the only explanation given being that the user was that “precise” with his shot.

In other words Captain America’s shield. Thor’s hammer ironically doesn’t count since the hammer is actually possessed, so it makes sense in his case.