Also, something I am working to clarify in my current campaign, is that a spring attack cannot be made around corners against opponents that you cannot see - migitaging circumstances 'could' include a spotter who tells you where your opponent is located, but I think that will still incur a penalty to the springer, as there's a lot of mis-calculation that can happen when he comes springing around the corner and his target isn't right where he thought it would be (or better yet, a new target ends up in an intervening position!). I also restrict the number of direction changes the springing character can make during the approach and release actions... never did make sense to me that a person could weave their way through 4 opponents, with 5 direction changes, so he could attack that mage "in the back"...