The Abyss

Version 0.28: This article may not be up to date for the latest stable release of Crawl.

The Abyss is a truly bizarre place, ever-changing and twisted. It is filled with all sorts of monsters, mostly of demonic nature, whose common aim is to feast on intruders. It is also the garbage dump for many sorcerers, who delight in sending would-be champions like you to these proving grounds of madness. Reportedly, there is some structure to the chaos, as Lugonu seems to concoct schemes around this place and its denizens. The Abyss consists of five infinite levels. The abyssal rune can be found from the third level onwards, and is more common at greater depths. The madness of the abyss prevents new vistors from gaining skills or gaining divine favour there. The Abyss can be purposefully reached through portals in the Depths. Portals back to the dungeon are scattered throughout the Abyss, and are found more commonly at greater depths or while carrying the abyssal rune. Killing monsters will warp the substance of the Abyss, eventually generating a gateway out. Further persistance will wear holes in the abyss, allowing descent into deeper layers.

A one-way gate to a demon-haunted realm, riven by chaos, its very substance impermanent and whimsical, filled with creatures out of nightmare.

The Abyss is an extra-dimensional chaotic plane without definite shape or form, inhabited by unholy horrors and ruled by Lugonu the Unformed. Whether you end up in this horrible place intentionally or as the result of sheer bad luck, dedicated explorers who manage to survive will eventually find the abyssal rune of Zot, and perhaps even a way out!

Structure

The Abyss is an unorthodox five-floor branch, with each "floor" an endless plane of constantly shifting terrain. Travel within or between levels of the Abyss is made difficult by several permanent branch features:

• No items spawn, outside of a player-created vault. Also, players may not gain XP or piety via regular means. This includes Gozag's gold touch, but Ashenzari and Ru sacrifices provide piety (but won't spawn new ones), and gods with transistory piety systems work normally: Uskayaw, Xom, and Yredelemnul.
• Abyssal stairs and branch exits appear rarely and at random. Killing enough monsters will force exits and eventually stairs to spawn. There are only descending staircases and portals leading out of the Abyss entirely, not stairs up.
• The terrain constantly changes, with individual wall tiles or large patches of wall appearing and disappearing from time to time. Your immediate surroundings will mostly retain their shape from turn to turn, however.
• Mapping the Abyss is impossible. Only tiles recently or currently in your line of sight are shown, and anything that leaves your sight is quickly forgotten.
• The player will be teleported at random intervals. 20% of the time, this teleport will reset the entire map. Sometimes, players will be forfully sent deeper into the abyss.
• You may occasionally see orderly structures in the Abyss. These vaults often contain powerful monsters, Abyssal stairs, the Abyssal rune, or even a way out. Approach these with caution as they are usually well-guarded.

Entering the Abyss

There are several ways to enter the Abyss; some are voluntary, most are not. Abyssal knights begin the game in Abyss:1, but can leave at will to Dungeon:1 with Lugonu's Depart the Abyss ability or risk searching for an exit. Lugonu worshipers can also travel to the Abyss at any time once they reach piety level ***** (for a large cost).

Other players must:

• Enter a portal in Pandemonium, a Labyrinth, or the Depths.
• Get banished by a monster spell.
• Unwield a distortion weapon (25% chance).
• Get hit by a distortion weapon (5% chance).
• Earn Lugonu's wrath.

Exploration and Exit

Exploration of the Abyss is not something to be attempted lightly. The branch is fairly dangerous; while higher level characters can easily survive extended trips here, characters under level 20 or so are usually underpowered to deal with the Abyss' inhabitants for very long. Unless your character has 100% mutation resistance, exploration of the Abyss puts you at risk of being malmutated by its inhabitants.

As you wander, you will eventually find Abyssal stairs leading further down. These deeper regions of the Abyss are significantly deadlier than the ones before, cranking up the monster generation rate. The Abyssal rune will eventually appear in A:3 and beyond, always in a vault, with higher odds at the deeper levels, but the greatly increased threat involved leaves players with little incentive to ever go any further than A:3. Lugonu worshipers with at least 5 stars of piety enjoy a significant boost to rune placement chance - they are treated as though they are exploring one floor deeper than normal. Be wary around any opponent capable of banishing you that you encounter in the Abyss, as being banished again will drive you down a floor.

If the rune has not been placed, the game makes a roll each time it would have placed a new item (if they could spawn). Any rune on the floor prevents the abyssal rune from being generated again. Rune placement probabilities:

• A:3 = 10 in 60 = 16% per item
• A:4 = 21 in 60 = 35% per item
• A:5 = 46 in 60 = 75% per item

Lugonu further increases the spawnrate of the rune.

Once you have the rune, exits will be discovered at a much faster rate. Branch exit spawning:

• A:1 = 1/7250 revealed tiles
• A:2 = 1/6000
• A:3 = 1/4750
• A:4 = 1/3500
• A:5 = 1/2250
• Holding Abyssal rune: 1/1000

Tips & Tricks

• The enemies found here are not much weaker than those found in Hell, so a full complement of resistances (particularly mutation resistance) is recommended. Getting surrounded here can be deadly, but if you can run away for long enough the level will reset, saving you from your pursuers. Having stealth may be useful, which can let you walk away from fights you just don't want to deal with.
• Getting sent to the Abyss early (usually through Banishment) is often a death sentence, but you may be able to survive long enough to find a gate out. For almost any player, surviving the Abyss is about mobility and not about XP or treasure. Use every speed advantage you can muster to avoid every combat you can; even if you can defeat some of the weaker foes, you want to spend every possible turn exploring new tiles and generating new chances of escape. When you see a monster, you should head in the opposite direction.
  • A means of flying over lava or deep water and a wand of digging will help manufacture avenues of escape when you're seemingly trapped. Since teleports take a while to kick in, consider teleporting on sight when you see speedy, lethal monsters like executioners or ranged threats like hell sentinels. Blinking can get you out of a nasty corner. Summons can slow/entangle pursuers. Use quiet dead ends to regenerate HP/MP. Then, get moving.
• When you're actually searching for the rune, consider sticking to Abyss:3 or 4 rather than delving all the way to Abyss:5. It may take a little longer, but the difference in monster spawn rate becomes dramatic once you hit bottom.
• The smartest way to survive the Abyss is to only enter it on your own terms. Read the page on Banishment for tips on avoiding one of Crawl's deadliest spells.

Monsters

• Almost any zombie or skeleton, usually of late-game monsters
• Almost any undead or non-fiend demon (though tier-1 demons are very rare)
• Rare player species monsters, such as tengu, octopodes, and deep dwarves
• Humanoid casters, such as wizards and necromancers
• Almost any eyeball
• Any kind of draconian
• Any uniques you banished to the Abyss
• Several monsters unique to the Abyss:

t Apocalypse crab	X Thrashing horror	X Starcursed mass	X Tentacled starspawn
x Ancient zyme	* Lurking horror	v Spatial maelstrom	* Wretched star

History

• In 0.28, the Abyss no longer provides items, XP (beyond opening gateways through the Abyss), or piety. Instead, collecting the rune provides 2 XL's worth of experience and some skill points.
• Prior to 0.25, if you spawned an Abyss exit without leaving/descending, you would always spawn stairs deeper by getting XP.
• Prior to 0.22, you could not be dragged deeper into the Abyss when being teleported.
• Prior to 0.18, killing monsters in the Abyss couldn't eventually spawn exits and down-stairs.
• Prior to 0.15, the Abyss would often cancel any attempt at blinking.
• Prior to 0.12, the Abyss had only one floor, and finding the rune was simply a matter of wandering it for long enough. Lava and deep water terrain could be generated.
• Prior to 0.10, the Abyss' terrain shifting would happen at a much slower pace, and only when you weren't looking directly at it.
• In earlier versions, the Abyss would wrap around on itself if you went too far in one direction. Also, banishment to the Abyss was one of the possible results of Hell's mystical force.