Constriction

Version 0.32: This article may not be up to date for the latest stable release of Crawl.

Constriction is the act of grabbing a target, preventing it from moving away, and crushing it to death over several turns. This lowers the evasion of the target, and prevents them from moving away.

List of constrictors

Monsters

• N Naga
• N Naga mage
• N Naga sharpshooter
• N Naga ritualist
• N Naga warrior
• N Nagaraja
• w Snaplasher vine
• S Ball python
• S Anaconda
• X Tentacled monstrosity
• w Starspawn tentacle
• J Formless jellyfish
• x Octopode
• N Vashnia
• x Erica
• Grasping Roots
  • g Jorgrun
  • f Shambling mangrove

Playable species

• Octopode
• Naga - gains the ability at experience level 13.

Forms

• Serpent talisman

Other Constriction Effects

• Borgnjor's Vile Clutch
• Wand of roots

Initiating Constriction

Melee Constriction

Constriction can occur whenever a constriction-capable character or monster makes a melee attack (not necessarily Unarmed Combat). All the following conditions apply:

• The attacker is not constricting another creature, unless the attacker is an Octopode. Octopodes are capable of maintaining up to eight at once (it doesn't matter if you wield weapons or shields).
• The defender is not constricted or engulfed by another creature.
• The attacker must be able to see the victim.
• The attacker is not confused.
• The size of the attacker is greater than or equal to the size of the defender.
• The defender is not immune to constriction attacks (see below).
• The defender must be next to the attacker (weapons of reaching don't allow you to constrict non-adjacent targets).

If all the previous requisites are met, the game rolls the to_hit of the attacker and the evasion/SH of the defender. For the player this is the standard auxiliary attack to_hit. It's calculated as follows:

to_hit = 13 + 0.75 * DEX + 0.3 * Fighting + Slaying bonus + Other bonuses

For the monsters, it's:

to_hit = 18 + 1.5 * HD + Other bonuses (replace 1.5 with 2.5 if the monster is a fighter i.e. naga warriors)

If the attack hits, the constriction starts, though monsters only have a 2/3 chance to apply constriction in melee.

Spell Constriction

For Borgnjor's Vile Clutch, wand of roots, or Grasping Roots, the following apply:

• The defender is not constricted or engulfed by another creature.
• The attacker must be able to see the victim.
• The defender is not immune to constriction attacks.
• The defender is not over deep water or lava.

These forms of constriction always hit.

Constriction Immunity

The following monsters are immune:

• jellies,
• spiny monsters,
• insubstantial monsters.

Player sources:

• insubstantial forms, like Storm Form or wisp form,
• the Spiny mutation, which is available only to demonspawn,
• Slick slippers unrand.

Maintaining Constriction

While the target is constricted, it will take damage each turn, will be unable to move in any direction, and will suffer a -10 evasion penalty. Attempting to move away will constitute an escape attempt, which for players has a 40% chance to succeed the first time. Subsequent escape attempts increase the chance to 75%, then 100%.

Damage Calculations

The amount of damage inflicted every 10 auts is:

 (Base damage) * (0.33 + 0.67 * (XL / 27))

• Base damage: For players constricting in melee, this is equal to 2d[(110 + (25 * XL)) / 81]. When using Borgnjor's Vile Clutch or a wand of roots, it depends of the power of the cast. For monsters, it is the base damage of that particular attack.
• Experience level modifier: The third factor means that your damage increases linearly with your experience level. A level 27 character will do thrice as much damage as one at level 1.

This damage is then modified as follows:

• AC reduction: Unlike most melee attacks, constriction is not reduced by a random number between 0 and AC; the damage reduction is a random number between 0 and 1 + AC / 2. This means that constriction bypasses half of the AC.
• Time scale: The previous formula calculates how much damage you do every 10 auts. That amount needs to be scaled depending on how many auts you have spent in this turn. For example: if you are attacking with a dagger at minimum delay (5 aut), the previous amount will be multiplied by 5/10 (after AC reduction).

Escaping Constriction

Along with simply succeeding at an escape attempt, there are a number of other methods for breaking free:

• Killing the constrictor.
• If the constrictor moves from its current tile, constriction ends (even if the destination is still adjacent to the constricted target).
  • The dispersal and distortion brands can force the constrictor to blink away (or be banished to the Abyss).
  • Casting Teleport Other, Dispersal or Disjunction has a similar effect.
  • Forcing the constrictor back with Iskenderun's Mystic Blast may also work but may not be as effective against larger monsters.
  • Casting Polar Vortex will force the enemy away from you much more aggressively.
  • Gell's gravitambourine can move a constrictor.
• Disabling the constrictor with confusion, paralysis, petrification, fear, unconsciousness, or polymorph immediately breaks constriction.
• Charming or Elyvilon's pacification.
• Becoming immune to constriction will immediately end the status.
  • Storm Form is immune to constriction.
  • Dragon Form is giant size, so it can only be constricted by tentacled monstrosities.
• Any source of blinking or teleport can get you free.
• Barachim can hop away, which will always escape constriction.
• Formicid's shaft ability will always escape constriction.
• Zin's Sanctuary ability breaks constriction.
• Ru's Draw Out Power and Power Leap will always escape construction.

History

• In 0.32, constriction was reworked. Prior to this version:
  • All player sources of constrict dealt less damage. However, any source of constriction damage increased over time when applied to monsters.
  • Escape chance for players used a more complex formula, and blinking and related effects did not guarantee escape.
  • Escape chance for monsters did not care about HD.
  • Constriction applied a -3 EV penalty to players and divided monster EV depending on size.
  • Player melee constriction cared about Str.
• Since 0.18, to-hit only depends on Dexterity.
• Prior to 0.12, the duration modifier to damage was applied to players.