It’s generally accepted as Best Practice to put a knot(s) in the ends of your rappel rope, to prevent the catastrophic accident of rapping off the ends. (This is also known as making a ”closed system”.)

Of course, if you’re rapping off a single pitch route and you can CLEARLY see that both ends of the rope are on the ground, a knot in the rope ends is not necessary. However, especially if you’re more of a beginning climber, it can be important to build good technique by repeating the same Best Practice all the time, so no one should chap on you if you decide to tie a knot in both ends of the rope.

There are a few different ways to approach this, and as with most aspects of climbing, no single one is right or wrong. Let’s explore each method and look at a few pros and cons.

Method 1 - Stopper knot in each strand

Method 2 - Tie both ends together

Method 3 - Clip both ends to your harness

Method 1 - Stopper knot in each strand

This is probably the most common technique. One benefit to this is that any twists generated by rappelling can work themselves out. 

However, there are two reasons why you might not want to do this.

1 -  A fairly common scenario that can lead to a Major Rappel Epic is forgetting to untie one or both knots in the rope before you start to pull the rope, and realizing, only too late, that you have a knot above you that will not pass through the rap anchor above.

F#$%^&*K!! Big Problem!!

(This usually happens when climbing with a new partner, when one of you likes to tie knots in the end of your rappel ropes, and the other one for some reason does not, and that other person decides to pull the rope without checking. Ask me how I know this . . . )

Do you or your partner REALLY want to put a prusik knot on that rope and ascend 60 meters, hoping like hell that stopper knot is somehow securely jammed in your anchor? The answer is NO, you definitely do not!

If you climb long enough, this will very likely happen to you, and hopefully you realize it FAST, when that damn knot is dangling only a couple of feet above your head, and you can do some crafty trick to pull it back down to you.

There are some ways to lower the chance of this happening.

• If your rappel ends on the ground, make it the task of the first person down to untie both of the knots. You don't need them anymore.

• If you have a multi pitch rappel, have the first person down use the “J loop” system: tie a figure 8 on a bight in both strands and clip it to the anchor. Now, the stopper nuts or no longer needed. The first person down can untie both of them, thread the pull strand threw the anchor, and tie one stopper knot in the new pull strand.

• Develop the habit of maintaining control of the strand that's going up until the last possible moment when it gets pulled out of your hands. If you're sloppy with this and let loose and swing out away from you on an overhang or blow away from you if it's windy, you might find that knot is out of your reach even if you haven't started pulling yet. You don't have to hold it in your hands, you could simply clip it through a quick draw attached to either you or the anchor.

Very unlikely but very serious: You may tie a knot in one rope strand and forget to tie a knot in the other.  If this were to happen, and the person rapping slides to the end of the rope, not only do they fall to the ground, they also could potentially pull the rope all the way through the anchor above, leaving your partner stranded. Depending on how remote your climb is, this could be an extremely serious situation.

Super important - ALWAYS be sure the knots in your rope are untied before you pull your rappel!

Note on stacked rappels and ONE stopper knot: This may well be the best solution of all for multi pitch rappelling: Both partners (or at least the second) use an extended rappel and pre-rig with an autoblock backup. Having the second person with their rappel device already on the rope and an autoblock fixes both strands of rope for the first person down, and the rope therefore can never slide through the anchor.

This means that you only need to tie a stopper knot in ONE strand of the rope. If the first person down were to rappel into the stopper knot for any reason, it can’t pull through the anchor because it's locked in place by the person above them. This also means that on multi pitch rappels, the first person down can thread the pull strand of the rope through the lower anchor, tie a stopper knot in it, and then pull the rope, which will pass through the upper anchor, and fall down past the lower anchor. No need to pull that strand back up to tie a second knot, a big time saver!

Method 2 - Tie both ends together

The solution to both of these problems is to tie both ends of the rope together. An flat overhand bend with about 1 foot of tail works fine.

This definitely eliminates problem number one, starting to pull the rope with a knot still in the end. If you start to pull the rope with both ends tied together, you have a closed loop, so you can easily retrieve it, untie the knot, and then continue pulling.

It also eliminates scenario number two, unlikely as it may be, because anyone who falls to the end of the rope is going to hit that knot and (probably) stop.

Many climbers dismiss this method because they think that twists in the road generated by rappelling have no way to work themselves out of the ends. The amount of rope twisting can vary a lot depending on the diameter and stiffness of your rope, your rappel device, etc., so experiment with this in a controlled environment and see how it works before you adopt it as a regular system.

Method 3 - Clip both ends to your harness

(advocated by Andy Kirkpatrick. See his great book, “1001 Climbing Tips, #252 for more.)

How about taking both ends of the rope and tying each one separately to your belay loop? This solves both the problem of rapping off the end of the rope and problem of pulling the rope before you untie the knot. If you get some twisting near the bottom, simply unclip the knots and continue down.

One clever modification to this, suggested by Andy: when attaching the rope ends, tie a figure 8 knot for the pull rope and an overhand knot for the other, to remind you which rope you're supposed to pull.

This gives an additional benefit: the rope is less likely to snag, because the rope is hanging in a loop below the rappeller.  With this method you you don't even need to throw the ropes. This makes it a good idea if there are climbers below you, it’s windy, you have a low angle rappel, or terrain with lots of shrubs, blocks etc. for the rope to hang up. Flake out the ropes carefully on your ledge, lower a bight of rope, the rappeller starts down, and the partner feeds out remaining rope as needed.

An additional benefit to this method is because you only have at most 30 meters of rope hanging below you, (assuming you're using a 60 meter rope) you're reducing the risk of damaging your rope if you knock off any rocks.

This technique can become more important in blocky terrain, high winds, low visibility, or if you're not sure where the next anchor is. Or some epic combination of these - basically, all the rappel situations that are Less Than Ideal.