# Wresting
When zapping or engraving with a wand that has no charges remaining, there is a 1 in 121 chance[1] that you will wrest another charge out of the wand, providing you with one last bit of magic after which the wand crumbles to dust. It is most commonly cited in connection with wands of wishing, where one last wish can be immensely useful; it is nevertheless possible with any wand.
A cancelled wand cannot be wrested from, as the internal charge counter is set to -1 by the act of cancellation.

Contents

1 Messages
2 Strategy
3 History
4 References

Messages
You wrest one last charge from the worn-out wand.
You were successful in wresting the final charge.
The 

<wand> turns to dust.
The wrested wand is destroyed, after the charge is wrested.
The <wand> glows violently, then turns to dust.  You are not going to get anywhere trying to write in the [dust|frost] with your dust.
You wrested the final charge whilst engraving. The wand crumbles to dust before you can engrave anything.
Strategy
The usual technique associated with wresting is to #adjust the wand to the z inventory slot and holding down the z key to zap the wand repeatedly, greatly reducing the amount of real time and effort needed to extract the wrested charge. Be sure to pay attention to what's going on around you while you hold down the key, or you may end up dead without knowing what killed you. Ideally you'd quickly tap the z key instead of holding it.
Tapping ctrl&nbsp;+ a (redo command) is an alternative to tapping z.
84 zaps are needed for a 50% chance of success.
It's not possible to use the wrested charge from a wand of fire, lightning, or digging to engrave with.
If you have the resources, it's a good idea to formally identify extremely valuable wands that you plan to recharge (e.g., wands of wishing) before zapping them enough times that they could potentially have reached 0 charges; while the 1/121 chance of discovering the wand is empty by accidentally wresting it is small, if you play enough games this will happen eventually!

History
Prior to 3.6.0, a useful alternative for non-directional wands such as wishing was to engrave with them while levitating, or to abort when prompted what text to engrave. Unsuccessful and canceled attempts to write did not consume a game turn, but did attempt to use the wand. This was bug C343-246. When levitating, adjusting the wand to E and holding down that key you will get your wrest very quickly. This is safe because the "You wrest one last charge from the worn-out wand." message triggers a more prompt. This made exploiting the bug much faster with levitation.

References

↑ src/zap.c in NetHack 3.6.6, line 2137

</wand></wand>