Hit chance
Hit chance is a calculated statistic that determines whether or not an attack will land. In its simplest form, hit chance is simply a function of accuracy, armour, and affinity; however, various modifiers (such as equipment or Buffs) can change hit chance.
When discussing changes to hit chance, modifiers are either additive (directly affecting hit chance) or multiplicative (affecting one of its variables). Additive bonuses are added directly the final calculation, whereas multiplicative bonuses modify a variable in the calculation. In this sense, accuracy is distinct from hit chance; the latter being a function of the former.
The hit chance formula[edit | edit source]
In combat, one's hit chance is the chance of successfully hitting a target (or the chance of a target hitting you), given your accuracy, the armour of your opponent, and the style you are using.
Your hit chance (as a percentage) is calculated as:
Where:
- is affinity
- is your accuracy
- is the target's armour rating. Generally, this is the sum of their armour and armour bonus granted by their Defence level.
Affinity[edit | edit source]
- Monster affinity
In player-versus-monster combat, the monster generally has an affinity set for 3 or 4 types of attacks: melee, magic, ranged, and the specific weakness, if it has one. By default, those values are:
- 90 when using the target's specific weakness. (eg. slash, stab, arrows, bolts, air, fire, etc.)
- 65 when using a combat style the target is weak against, but not the specific weakness (eg. melee against a ranger)
- 55 when using a combat style the target is neutral against (eg. melee against a meleer)
- 45 when using a combat style the target is strong against (eg. melee against a mage)
Generic weaknesses to melee, ranged, or magic will use the respective melee, ranged, and magic affinity value rather than the weakness affinity value.
Some NPCs have custom set values for each affinity. For example, some bosses have 40 on all affinity values. Sometimes they may have no set weakness, but the affinities favour (or disfavour) one combat style anyway.
- Player affinity
When the target is a player - be that in player-versus-player combat, or when calculating your defending chance in PvM - affinity is calculated a little differently. The neutral affinity is still 55, and up to 10 points are added or subtracted based on the armour the target is wearing for each of the three combat styles - players never have a specific weakness. The player's affinity is shown as Style bonus in the loadout interface; see Affinity#Player affinity and style bonus for details on calculating the actual affinity from style bonus.
Calculating accuracy[edit | edit source]
A players total accuracy stat is the sum of their level bonus and weapon tier bonus . Both of these values involve the formula . If the player has level in the relevant attack skill (attack, ranged, or magic), their level bonus is just (rounded down). For example, a player with 99 attack and no weapon equipped will have (rounded) accuracy . Temporary boosts such as overloads and stat-boosting prayers will affect this value. The level-based bonus for a player with level 99 attack/magic/ranged is shown below for various boosts.
The accuracy boost from by the player's weapon tier is generally much larger. A weapon of tier accuracy gives an accuracy boost of . For example, if the player has level 99 ranged and is using a tier 92 bow, then their resulting accuracy is (rounded down). For example, if a player has 99 ranged and is using a tier 92 bow, they will have an accuracy of 3789 (which is rounded down. If a potion temporarily raises their ranged level to 120, they will have temporarily have an accuracy level of 4360 (which is rounded down).
Weapon tier | Weapon accuracy bonus |
---|---|
70 | 1486 |
75 | 1694 |
80 | 1924 |
85 | 2178 |
90 | 2458 |
92 | 2577 |
99 | 3031 |
Equipment penalty[edit | edit source]
Wearing armour of the wrong class, excluding hybrid class, will negatively impact hit chance. Affected item slots include the helm, torso, legs, feet, hands, and off-hand slot. Depending on the weapon type, wearing armour from the class you are strong against (ie. if using Melee, this is Ranged) will result in an accuracy penalty that is 3/2 (x1.5) the item's armour stat. Wearing armour of the class you are weak against (if using Melee, this is Magic) will result in an accuracy penalty that is 4/5 (x0.8) of that item's armour stat. This penalty is designed to reinforce the combat triangle system and to prevent players from abusing the combat triangle weaknesses.
Accuracy boosts[edit | edit source]
There are various things that can be used to increase your accuracy rating; these simply multiply your accuracy value by a number, and these can be stacked with one another. These include:
Hit chance boosts[edit | edit source]
Also known as flat or additive accuracy bonuses. Unlike the above mentioned accuracy bonuses, these add the value directly to your final hit chance, rather than multiplying it. These can also be stacked with one another.
For example, a 10% hit chance bonus adds 10% to 60%, thus becoming 70% hit chance.
Item | Addition | Combat Style |
---|---|---|
Keris (against Kalphites, also 33.3% damage boost and 2.5% chance to deal +200% damage instead +33.3%) | 15% | Melee |
Silverlight, Darklight, and Holy water (against certain demons, also a large damage boost) | 20% | Melee/Ranged |
Keris with Desert amulet 3 or Desert amulet 4 worn (against Kalphites, also 33.3% damage boost and 5% chance to deal +200% damage instead of +33.3%) | 25% | Melee |
Darklight and Holy water (against certain demons; with the Darklight upgrade reward from Dimension of Disaster, also a large damage boost) | 30% | Melee/Ranged |
Balmung (against Dagannoths, also 12.5% ability damage boost (7.5% against Dagannoth Supreme)) | 30% | Melee |
Upgraded Balmung (against Dagannoths, also 22.5% ability damage boost (17.5% against Dagannoth Supreme)) | 45% | Melee |
Dazing Shot and Greater Dazing Shot | -10% on your target's next attack | Ranged |
Hexhunter bow (against magic-classed targets, also 12.5% damage boost) | 10% | Ranged |
Nightmare gauntlets | 25% to Snipe, as well as allowing movement | Ranged |
Fleeting boots and Enhanced fleeting boots | 10% to Rapid fire, as well as allowing movement | Ranged |
Bane ammo (against their attuned targets (Dragons, Abyssal, Basilisks, Wallasalkis), also 25% ability damage boost or 40% boost to auto-attacks) | 30% | Ranged |
Confuse | -5% for the affected target | Magic |
Stagger | -10% for the affected target | Magic |
Sonic Wave | 6% on your next attack | Magic |
Reaper necklace | 0.1% per stack (3% max) | Any |
Offensive Ultimate Abilities (Omnipower, Meteor Strike, Onslaught, etc) | 25% | Any |
Blisterwood weapons and Sunspear variants (against vampyres, vyrewatch, vyrelords/ladies, also chance to deal +100% damage) | 50% | Any |
Affinity modifiers[edit | edit source]
The following items and abilities increase the target's affinity, thereby making it easier to hit them. Only one of each can be active at once, and they stack additively with each other (i.e. using quake twice won't apply a +4 debuff, but quake with a barrelchest anchor special attack would be +6) up to a maximum of +10. Using the ability again refreshes the duration.
Effect | Debuff amount |
Duration |
---|---|---|
Abilities | ||
Quake | +2 | 1 minute |
Special attacks | ||
Guthix staff | +2 | 1 minute |
Statius warhammer | +5 | 1 minute |
Dragon hatchet | +3 | 1 minute |
Barrelchest anchor | +4 | 1 minute |
Bone dagger | +2 | 1 minute |
Passives | ||
(Illuminated) Bandos's Book of War | +3 | 12 seconds |
Hit chance examples[edit | edit source]
Using Saradomin godsword (slash style) at Abyssal demon (slash weakness) with 99 attack:
hit chance is capped at 100%, so all attacks will not miss.
On the other hand, using Sunspear (ranged) with 99 ranged in void knight armour will result in misses:
For a Queen Black Dragon bossing situation, using Royal crossbow, Overload, Anguish, and Royal bolts with 99 ranged will result in misses:
Swapping for Dragonbane bolt will provide an additive bonus to hit chance:
and, therefore, reaching hit cap.
Boss armour ratings[edit | edit source]
The tables below are for quick look-up of the total armour rating of current bosses. For the affinity values to your combat style, refer to the boss's individual page. HM and CM refers to hard mode and challenge mode, respectively.
God Wars Dungeon 1[edit | edit source]
Bosses include: Commander Zilyana, General Graardor, Kree'arra, K'ril Tsutsaroth, and Nex.
Boss | F(![]() |
Armour | Total |
---|---|---|---|
Normal Mode | 678 | 1299 | 1977 |
Hard Mode | 678 | 1694 | 2372 |
Nex | 770 | 1924 | 2694 |
Nex (Aod) | 1212 | 2765 | 3977 |
God Wars Dungeon 2[edit | edit source]
The stats shown for Vindicta are for her second phase, which are higher than the first.
Boss | F(![]() |
Armour | Total |
---|---|---|---|
Gregorovic | 678 | 1694 | 2372 |
Gregorovic (CM) | 770 | 1924 | 2694 |
Helwyr | 594 | 1486 | 2080 |
Helwyr (CM) | 678 | 1694 | 2372 |
Twin Furies | 594 | 1486 | 2080 |
Twin Furies (CM) | 678 | 1486 | 2164 |
Vindicta | 770 | 1924 | 2694 |
Telos | 770 | 1924 | 2694 |
Raids[edit | edit source]
Boss | F(![]() |
Armour | Total |
---|---|---|---|
Beastmaster Durzag | 1106 | 2458 | 3564 |
Yakamaru | 1212 | 2765 | 3977 |
Solo/Duo[edit | edit source]
Boss | F(![]() |
Armour | Total |
---|---|---|---|
The Magister | 1031 | 2577 | 3608 |
Araxxor | 871 | 2458 | 3329 |
Araxxi | 770 | 1924 | 2694 |
Har-Aken | 770 | 1924 | 2694 |
Queen Black Dragon | 770 | 2074 | 2844 |
Group[edit | edit source]
Boss | F(![]() |
Armour | Total |
---|---|---|---|
Chaos Elemental | 579 | 1447 | 2026 |
Corporeal Beast | 678 | 1694 | 2372 |
Giant mole | 293 | 732 | 1025 |
Dagannoth Kings | 564 | 1409 | 1973 |
Kalphite King | 871 | 2178 | 3049 |
Kalphite Queen | 594 | 1486 | 2080 |
Exiled Kalphite Queen | 678 | 1694 | 2372 |
King Black Dragon | 453 | 1132 | 1585 |
Vorago | 983 | 2178 | 3161 |
Update history[edit | edit source]
- patch 1 September 2020 (Update):
- Hit chance modifiers are now recalculated right after the 'Stagger' spell, 'Confuse' spell, or the Sandstorm Camel Debuff hits the target in PvP.
- patch 12 September 2016 (Update):
- Lowered the base hit-chance bonuses from some effects:
- Statius's Warhammer special attack, 10% -> 5%
- Dragon hatchet special attack, 5% to 3%
- Barrelchest anchor special attack, 5% to 4%
- Bone dagger special attack, 5% to 2%
- Bandos'/Illuminated book of war random effect, 5% to 3%
- Lowered the base hit-chance bonuses from some effects:
Modes |
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Calculations | |
Equipment | |
Mechanics | |
Miscellaneous |
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