A leash is a tool for keeping your pets close to you, especially when using stairs or portals. You may only have 2 leashed pets at one time. A cursed leash cannot be removed and will strangle the pet if it gets too far away (for example, because it hit a teleport trap). A noncursed leash will harmlessly snap loose if you become too far removed from your pet. To remove a leash from a pet, simply apply it to that pet.
A leashed pet will not want to move more than 2 squares away from you. Be aware that leashed pets will also not attack monsters that are not adjacent to you, unless that monster is exactly 2 cells above, below, or to the side of you. See below:
------- ------ ------- ------- |...... |...... |...... |kkkkk. |.....| |.....| |.....| |kkkkk| |..k..| |.....| |..f..| |kkfkk| |.kfk.| |..kk.| |.kkk.| |k...k| |.k@k.| |..@fk| |..@..| |kk@kk| |.....| |..kk.| |.....| |kkkkk| |.----- |.----- |.----- |.-----
The first three examples show where a monster could be attacked by your kitten. The fourth example shows where your kitten will not attack the kobold.
A leash is useful for curse-testing items with the aid of a pet - it makes it possible to drag the pet over the item to see whether it "moves only reluctantly". However, leashed or whistled pets need not always give the "moves only reluctantly" message for cursed items. It can also be used to encourage pets to steal from shops, by dragging them out of the shop while they're still holding an item. The leash can also make it easier to displace your pet into a polymorph trap.
A leashed dog might "whine" if there is a trap nearby, even if you have not yet detected the trap. A leashed cat will "whimper", and other pets can make appropriate nervous sounds around traps.
If you move too far away from your leashed pet, it may "yowl" or make some other angry noise. This is purely cosmetic, it cannot wake up sleeping monsters or reduce tameness. Pay attention when your pet is eating, or when going through doorways or around corners. If you move much faster than your pet, this will happen frequently. It is possible to drag leashed pets through closed doors. This is a bug that is marked fixed.
Protection runners often desire a leash so they can dig down and bypass dark mines levels. Alternatively, if you have only one pet, you can dig two squares' length of corridor into rock, displace your pet into the end, and dig down. It will stay adjacent and fall down with you.
Encyclopedia entry Edit
They had splendid heads, fine shoulders, strong legs, and
straight tails. The spots on their bodies were jet-black and
mostly the size of a two-shilling piece; they had smaller
spots on their heads, legs, and tails. Their noses and eye-
rims were black. Missis had a most winning expression.
Pongo, though a dog born to command, had a twinkle in his
eye. They walked side by side with great dignity, only
putting the Dearlys on the leash to lead them over crossings.