Someone earlier mentioned about having the king move to the corner rather than any edge. Here http://www.ludoteka.com/tablut-en.html is an example of the game played at the corners rather than the edges. As you can see the rules of capture become slightly more complex, but perhaps it could be another Tablut variant at BrainKing?
(hide) If you are waiting for your turn, click on "change" next to the "refresh" on the main page, then set refresh the page to 30 seconds to get your turn to move displayed faster. (Servant) (show all tips)