This is a way to shorten rope that my friend and I came up with while we were at a scout camp.
It is a chain of slipknots that will come either come undone when both ends are pulled simultaneously or stay together when the end is knotted
(This is my first instructable so be vicious with what i could improve)

Step 1: Materials

All you need to do this is a length of rope that you want shortened and about 5 to 10 minutes of time depending on the length of the rope

Step 2: Beginning the Chain

To begin make a loop in the rope with the short end of the rop passing over the long end to the left

Then using the long side make a bend near the loop

Next pass the bend through the loop and pull and then pull it tight creating another loop
(to tighten pull on the side that is not loos in this case the left one)

Now make another bend in the long part of the rop and pass it through the loop you just created then tighten it.

Step 3: Continuing the Chain

Now simply repeat until you have reached the end of the rope or until you get bored.

Step 4: Undoing the "Slip Chain"

To undo the chain simply grab hold of the two loose ends and pull them away from each other
and the chain will come apart
(if the chain is pulled overly tight it may be a little harder to pull apart)

Step 5: Locking the Chain

To lock the chain so that it does not come undone is simple.
Instead of making a bend and passing it through the loop
take the end of the rope and pass it through the loop

Step 6: Enjoy

Heres a Video of the chain being undone

Thanks go out to
My friend for helping me design this
My Scoutmaster fro providing more rope when we broke the first
and to you fro taking the time to read this