Difference between revisions of "To hit"

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(Base Value: A bit short on the new formula, but removed all the mentions of strength weighting.)
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'''To hit''' (short for 'chance to hit') is the probability that an attack will hit a target. It is one of the two key factors in determining the success of an attack, the other being damage.
 
'''To hit''' (short for 'chance to hit') is the probability that an attack will hit a target. It is one of the two key factors in determining the success of an attack, the other being damage.
  
The to hit can be calculated for melee and ranged attacks, and is calculated differently for players and monsters.
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The to hit can be calculated for melee and ranged attacks, and is calculated differently for players and monsters.  The largest factors for players are weapon (or unarmed) skill and fighting skill - with good training on both skills and decent dexterity, it should be rare to miss most targets.
  
==Player To Hit (Melee)==
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==To-hit vs EV==
The player's to-hit in melee is determined by the following factors:
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The higher an attack's to-hit is compared to the opponent's [[evasion]], the more likely the attack is to land:<ref>{{source ref|0.30.0|attack.cc|1197}}</ref>
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*2.5% of the time, the attack misses regardless of the attack's to-hit or the defender's EV.
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*2.5% of the time, the attack hits regardless of the attack's to-hit or the defender's EV.
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*Else, the game checks if <code>1d(to-hit + 1) - 1 ≥ 2d(2 * EV - 1)/2</code>. If this equation is true, then the attack hits. Otherwise the attack misses.
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==Player To Hit (Weapons)==
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The player's to-hit in melee and ranged combat is determined by the following factors:
  
 
====Base Value====
 
====Base Value====
Since the removal of strength weighting, base to hit is determined by your dexterity and the accuracy value of your weapon.
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*Start with <code>14 + dex/2 + 1d(Fighting + 1)</code>.
  
 
====Weapons====
 
====Weapons====
*If not wielding a weapon, the player gets:
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*Add <code>1d(weapon skill + 1) -1 </code> (number from 0 to weapon skill).
**Between +0 and +[[Unarmed Combat]]
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*Add weapon base accuracy. (Unarmed has +2, or +4 with [[Claws]])
***+4 if a [[troll]], [[felid]] or [[ghoul]]
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*Add weapon [[enchant]]ment and any [[slaying]] bonuses.
***+2 if any other species
 
*If wielding a weapon, the player gets that weapon's intrinsic accuracy, plus any enchantment (the plus on the weapon).
 
 
 
====Jewellery====
 
*If the player is wearing an [[amulet of inaccuracy]], they get a -5 penalty.
 
*If the player is wearing a [[ring of slaying]], they get the ring's hit bonus/penalty.
 
 
 
====Skills====
 
*[[Fighting]] gives you a bonus of +0 to +Fighting.
 
*Weapon skills give you a bonus of +0 to +Your Skill (if you are wielding the matching weapon).
 
  
====Environmental====
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====Other modifiers====
*When both combatants are in water and only the player is capable of swimming, the player get a +5 bonus.
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*If in wisp, fungus, pig, or non-vampire bat form, add random2(XL*100+100)/100 instead of using your weapon skill above.
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*Subtract 5 for [[vertigo]].
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*If you have the eyeballs mutation, add <code>2*eyeballs_level + 1</code>
  
====Status Effects====
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====The Roll====
*If the player is starving, they get a -3 penalty.
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*Take this total and roll <code>1d(total) - 1</code>.
*If the player is invisible but cannot [[see invisible]], they get a -5 penalty (because they cannot see what they are doing).
 
  
====Shield Penalty====
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====Post Roll====
*The player's shield penalty is -1d(ASP) where ASP is the Adjusted Shield Penalty. It is ASP = (Shield EV penalty) - (Shields skill)/(5 + (Size factor)) as explained in the [[Shields]] page. This penalty can be removed completely with enough skill levels in Shields.
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*Subtract 5 from wearing the [[Amulet of the Air]] or if you [[Ru#Sacrifices|Sacrificed Eye]] for Ru.
 
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*Subtract 5 if confused.
====Armour Penalty====
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*Subtract 6 if you cannot see the target (invisibility).
*The player's [[armour]] penalty is then calculated: -1d(ABAP) where ABAP is the Adjusted Body Armour Penalty.  
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*Add 2 + roll between 0 and 7 if the target is backlit ([[Corona]], [[Sticky Flame]], or under a [[halo]]).
ABAP = (body_armour_base_penalty + max(0, 3*body_armour_base_penalty - str)) * (45 - armour_skill)/45
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*Subtract 2 + roll between 0 and 3 if the target is in umbra and you do not have night vision (from Dithmenos & Yredelemnul).
 
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*The [[Confusing Touch]] spell grants +0 to +(DEX-1).
[[Barding]] does not affect the to hit penalty despite having an evasion modifier.
 
 
 
====Mutation bonus====
 
*If the player has the [[Jiyva_mutations#Eyeballs|Eyeballs]] mutation they get a +3/+5/+7 bonus.
 
 
 
===The Roll===
 
This completes the to hit calculation. The value is now 'rolled' (ie. a number from 0 to ''to hit''-1 is randomly generated). If this number exceeds the evasion value of the monster they are attacking, they hit lands.
 
 
 
====Post-Roll====
 
There are additional effects which can modify the to hit score AFTER it has been rolled:
 
*If the player is bonded to their weapon with the [[Sure Blade]] spell, they get +(5 + remaining duration of Sure Blade (MAX: +15)).
 
*If the player is not wielding a weapon:
 
**The [[Confusing Touch]] spell grants +0 to +(DEX-1).
 
 
**Being in the following forms grant bonuses:
 
**Being in the following forms grant bonuses:
 
***[[Statue Form]]: 0 to +8
 
***[[Statue Form]]: 0 to +8
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***[[Tree Form]]: 0 to +9
 
***[[Tree Form]]: 0 to +9
 
***[[Wisp Form]]: 0 to +9
 
***[[Wisp Form]]: 0 to +9
 
*Attacking a target under the effects of the [[Corona]] spell grants +2 to +9.
 
*Attacking an invisible monster without being able to see invisible gives you -6.
 
  
 
==Monster To Hit (Melee)==
 
==Monster To Hit (Melee)==
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===Hit Dice===
 
===Hit Dice===
Monsters with the Fighter class flag get a bonus of +(2.5 * [[HD]]). Other monsters get +(1.5 * HD). Decimals are rounded down.
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Monsters with the [[Fighter flag|Fighter class flag]] get a bonus of +(2.5 * [[HD]]). Other monsters get +(1.5 * HD). Decimals are rounded down.
  
 
===Situational Modifiers===
 
===Situational Modifiers===
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Ranged attacks ("beams", to use the game's internal terminology) have a to hit number, just like melee attacks do. This is modified as follows:
 
Ranged attacks ("beams", to use the game's internal terminology) have a to hit number, just like melee attacks do. This is modified as follows:
 
*If you are invisible and the attacker can't see invisible, the to hit number is halved.
 
*If you are invisible and the attacker can't see invisible, the to hit number is halved.
*If you have [[Deflect Missiles]] running, the to hit number is reduced to a random number between 0 and 2/3 of its value.
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*If you have [[Repel Missiles]], the to hit number is reduced ''by'' a random number between 0 and 1/2 of its value (rounded down).
*If you don't have Deflect Missiles running, but do have [[Repel Missiles]] running or the Repulsion Field mutation at level 3, the to hit number is reduced ''by'' a random number between 0 and 1/2 of its value (rounded down).
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==References==
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<references />
  
 
[[Category:Game_mechanics]]
 
[[Category:Game_mechanics]]

Latest revision as of 22:00, 2 July 2023

Version 0.30: This article may not be up to date for the latest stable release of Crawl.

To hit (short for 'chance to hit') is the probability that an attack will hit a target. It is one of the two key factors in determining the success of an attack, the other being damage.

The to hit can be calculated for melee and ranged attacks, and is calculated differently for players and monsters. The largest factors for players are weapon (or unarmed) skill and fighting skill - with good training on both skills and decent dexterity, it should be rare to miss most targets.

To-hit vs EV

The higher an attack's to-hit is compared to the opponent's evasion, the more likely the attack is to land:[1]

  • 2.5% of the time, the attack misses regardless of the attack's to-hit or the defender's EV.
  • 2.5% of the time, the attack hits regardless of the attack's to-hit or the defender's EV.
  • Else, the game checks if 1d(to-hit + 1) - 1 ≥ 2d(2 * EV - 1)/2. If this equation is true, then the attack hits. Otherwise the attack misses.

Player To Hit (Weapons)

The player's to-hit in melee and ranged combat is determined by the following factors:

Base Value

  • Start with 14 + dex/2 + 1d(Fighting + 1).

Weapons

  • Add 1d(weapon skill + 1) -1 (number from 0 to weapon skill).
  • Add weapon base accuracy. (Unarmed has +2, or +4 with Claws)
  • Add weapon enchantment and any slaying bonuses.

Other modifiers

  • If in wisp, fungus, pig, or non-vampire bat form, add random2(XL*100+100)/100 instead of using your weapon skill above.
  • Subtract 5 for vertigo.
  • If you have the eyeballs mutation, add 2*eyeballs_level + 1

The Roll

  • Take this total and roll 1d(total) - 1.

Post Roll

Monster To Hit (Melee)

A monster's to hit is calculated as follows:

Base Value

The base value is 18.

Hit Dice

Monsters with the Fighter class flag get a bonus of +(2.5 * HD). Other monsters get +(1.5 * HD). Decimals are rounded down.

Situational Modifiers

  • An aquatic monster "using the terrain to its advantage" gets +5.
  • A monster wielding a weapon receives that weapon's inherent and magical to hit modifiers.
  • A confused monster gets -5.
  • A monster attacking a backlit defender gets +2 to +9.
  • A monster attacking an invisible target suffers a 35% penalty to its to hit number.

Monster To Hit (Ranged)

Ranged attacks ("beams", to use the game's internal terminology) have a to hit number, just like melee attacks do. This is modified as follows:

  • If you are invisible and the attacker can't see invisible, the to hit number is halved.
  • If you have Repel Missiles, the to hit number is reduced by a random number between 0 and 1/2 of its value (rounded down).

References

  1. attack.cc:1197 (0.30.0)