I've been tinkering on and off with a javascript hack that I hope would prevent swiping through files/chapters, but I could never get it to work right. There's not alot of documentation even saying what javascript is permitted in epub... there are a few of the Jackson Fighting Fantasy books that I'd like to convert and keep the hit points and dice rolls entirely within epub (I think CYOA had this as well with a "flip a coin and if it's heads turn to page X").

Oh well.