When a player is killed by a giant spider and leaves bones, there will be a web trap placed on their square, and occasionally one or two giant spider eggs.

When wielding Sting, you should be able to untrap adjacent webs and monsters stuck in those webs with 100% success.

Projectiles of any sort that pass over a web space may stop there and drop on the space, getting “caught in the web”.

Traps track the turn on which they were created in the trap struct. This is used to determine the age of a web; creatures will tear through an older web more easily, and with less strength, than a young one.

(Possibly, when you spend time off-level, this trap timestamp updates to account for that time, because time is frozen when you aren’t on a level.)

When you read a scroll of web, you are repeatedly given a getpos prompt for where you would like to create a web. The area in which you can create webs is identical to the scroll of stinking cloud in terms of line of sight and radius. Each position you select has a web placed on it (though if will fail if a web can’t be placed there for whatever reason, such as another trap already existing there). If you create a web on a square containing a monster, it is immediately entangled in the web.

The amount of webs you can place is 2 if the scroll is cursed, 6 if it is uncursed, and 10 if it is blessed.

You can force-fight a web to cut it, which may occasionally fail and get you or the weapon stuck in the web.

If there is a web over water or lava and you are a web-walking monster, you can move onto that space without falling into the liquid. Possibly if you’re any monster, not just a web walker.

Lighting a web on fire will burn it away, and also spread to any adjacent webs and burn through them. Monsters on squares containing burning webs take a smallish amount of fire damage.

Spider nest room; a zoo-type room (where every square generates a monster independently) with giant and cave spiders. Each square additionally has a 70% chance of a web. Loot consists of several “bones piles” that have a few random objects but no comestibles.

Creatures that are stuck in a web (either the player or monsters) get a to-hit penalty.

Spiders have an attack that wraps you in a web (using sticky attack behavior?) or creates a web on your square and traps you in it, so you can’t move.

See also #1409, which discusses a similar idea where spiders can do this sort of thing at range.

Spiders can spin webs as they move along (cave spiders with less frequency than giant spiders.) This chance is boosted if they move into a doorway or choke point.

Oilskin cloaks prevent you from getting entangled in webs. Greased cloaks do too, but the grease may wear off in the process.

The scroll and spellbook of web allow you to fire a web projectile (which would work similarly to a venom projectile, probably also being in VENOM_CLASS) or beam in a direction. If it hits a wall, it creates a web on the last non-wall space; if it hits a monster it creates a web on the monster’s space and immediately entangles it. If it goes far enough without hitting anything, it creates a web at the end of its range.

Giant spiders should possibly also be able to shoot a web like this, and if so the player should be able to do it via #monster when polymorphed into one.

Electric spider that, when it stands on a web, can electrify that web and all contiguous ones, dealing shock damage to anything in it.

Boulders tear through spider webs (whether from a rolling boulder trap, thrown by a giant, or pushed by the hero). For extra realism, the web slows its momentum.

Add nets, on the basis that NetHack needs to have nets in it. You can throw them in pools to fish with, and throw them at small monsters to trap them in place. There could also be a trap that catches you in a net. You can also mess up throwing them and tangle yourself instead. Possibly, nets would be their own skill too.

For simplicity of implementation, they should create a temporary web on the player’s space (with a flag set so that it uses “net” in its messages instead of “web” and is probably harder/impossible to tear through at high Strength). Either nets would generate in stacks of 11-20 and get destroyed when the monster escaped the net, or they would drop themselves (most of the time) when the monster escaped the net and destroyed the trap. Either way, they should be fairly light.

Setting fire to a web should burn through it, spreading to any adjacent webs and destroying all of them.

When “Sting cuts through a web!”, the web is destroyed. Currently it only allows you to escape the web in 1 turn and does not destroy it.