Health

Each segment of the health bar represents at most 100 health.

Health (commonly known as HP, an abbreviation for Health/Hit Points) is the amount of life a unit or structure has. Max health is the cap on life any unit can have. Current health is directly reduced by damage and is regained in many different ways.

Every unit and structure has their max health and current health displayed as a bar above their models. When displayed over a champion's model in game, the health meter is displayed as segmented bars.

The green health bar on top, and the blue mana bar at the bottom.

Additionally, for your own champion, it is represented in the interface as a green bar with two numbers ( # / # ): the first one represents the actual life available at the moment, while the second is the maximum amount of health the champion can have. If a champion's health reaches zero and he doesn't have any abilities preventing it, death will occur. Max health scales additively with every bonus health point and increases with each level, meaning that each bonus point acquired directly affects the statistic.

At level 18 base health ranges from Gnar's 1645 health to Alistar's 2347.4 health. See here for the complete list.

Maximum health has a gold value of 2.67 per point. Health regeneration has a gold value of 36 per point. Health restored by potion has a gold value of 0.233 per point.

Effective health

Effective burst health, commonly referred to just as effective health, describes the amount of raw burst damage a champion can receive before dying in such a short time span that he remains unaffected by any form of health restoration (even if the actual considered damage is of sustained form). It can however include any form of health gain (such as from Nasus' Fury of the Sands). Effective sustained health, on the other hand, would take into account also champion's health restoration.

Unless champion's resists aren't unnaturally reduced below zero, any effective health will always be more than or equal to a champion's displayed health in their health bar and it can be increased by buying items with extra health, armor and magic resistance.

Depending on the type of damage taken, we can also speak of physical effective health, magical effective health or mixed effective health. Depending on a behavior of such source of damage it is also possible to speak of effective health relative to given subject/source of damage, for example magical effective health versus poke. Many poke team compositions with mixed overall damage usually heavily rely on a poke consisting of prevalent magic damage. Maximizing primarily magical effective health thus might be a valuable counterstrategy to weaken their poking phase as teamfight initiation relies upon it.

Effective health is a measure of the durability of a champion, taking into account their health as well as their armor and magic resistance. 'Sheer' forms of effective health are defined as health plus 1% of health for every point of armor (or magic resistance). Contrary to their simple formulas, mixed effective health uses a bit more complex one. Because of this, mixed effective health is always subject to the damage source and the proportions between particular three damage composites (with pure damage being regarded as true damage). The formulae are as follows:

physical effective health = HP × (1 + 0.01 × armor)
magical effective health = HP × (1 + 0.01 × MR)

The formula for mixed effective health can be simply derived from the effective health : nominal health ratio which is always the same as ratio of damage dealt : damage taken (after application of resists):

$\pagecolor{Black}\color{White}{\rm mixed\ effective\ health}={\it HP}\times{ {physical\ damage+true\ damage+magic\ damage}\over{ {physical\ damage\over{1+0.01\times{\it armor} } }+true\ damage+{magic\ damage\over{1+0.01\times{\it MR} } } } }$

Note: One can include the penetrations in all of the above ideas by replacing penetration with a due amount of corresponding negative resist.

Physical effective health and magical effective health are effective against physical damage and magic damage, respectively. They correspond to the amount of damage that an enemy champion must output (not the amount you must take) to bring your health to 0.

Example: If you have 1000 health, then purchasing 90 armor will raise your physical effective health to 1900. Enemies will have to output 90% more physical damage than usual to kill you.

Optimal efficiency (theoretical)

Note: Optimal efficiencies against only specific types of damage are located in the corresponding sections under armor and under magic resistance, respectively. In this article, effective health will simply refer to the mixed effective burst health, or the amount of cocktail of raw burst 'physical damage', 'true/pure damage' and 'magic damage' a champion can take before dying.

We will be further considering effective health against the mix of physical damage, true damage and magic damage, with ratio of P : T : M, respectively. As the following analysis would lead to polynomials of very high degree with general formula for effective health, and as true damage is a very strong damage type- and therefore a strongly restricted resource, we will further assume that its amount is not significant and put T = 0 (hence the results of this section will poorly apply to fights happening under Nexus Obelisk). That means that in reality the odds will be slightly shifting in favor of building health, depending on the amount of omitted true damage.

Note: The ratios of mixed damage taken into account can be quite accurately estimated by using kill-recap screen or end-game champ info on damage taken, as well as end-game enemy (team) info on damage dealt. As the composition of mixed damage can highly fluctuate over time between laning, poking, all-ins, diving or teamfight phases, the provided statistics (as always) must be taken into account with precaution. Lastly, some of these statistics won't include minions', monsters' or turrets' mostly physical damage (with exceptions of Template:Mois mixed damage and Nexus Obelisk's pure damage), which also poses a large portion of early game damage. When accessing champion damage composition from runes, masteries and items, the important factor in the current season is that keystones like Thunderlord's Decree, Deathfire Torch or Grasp of Undying can add large portions of (even scaling) magic damage for strict AD champion and vice versa- keystone like Fervor of Battle will add large portion of physical damage even on strict AP champion.

In the game players buy HP, armor and MR for gold. As gold value of armor (derived from cost of basic armor item) is currently (as of season six) 7.5 times higher than gold value of HP (derived from cost of basic health item), and gold value of MR (derived from cost of basic magic resistance item) is currently 6.75 times higher than gold value of HP, we theoretically can maximize effective health represented by the formula above with gold as input variable by satisfying the following equations:

$\pagecolor {Black}\color {White}7.5\times {{100+{\it {A}}} \over {\sqrt {10{\it {P}}}}}={{\it {HP}} \over {{\sqrt {10{\it {P}}}}+{\sqrt {9{\it {M}}}}}}=6.75\times {{100+{\it {MR}}} \over {\sqrt {9{\it {M}}}}}$

Example: We can derive from these equations that to efficiently defend against mixed damage composed of exactly 50% physical damage and 50% magic damage, magic resistance value of the ideal build would be approximately 5% greater than that of armor.

These equations define the base equilibrium line of optimal mixed effective health against damage source with composition ratio of P : 0 : M.

Example: Given a theoretical situation where you start off with 0 health, 0 magic resistance and 0 armor and are given an arbitrary sufficient amount of gold ( ≥ 4 × max{ 10 × (100 + armor) × (1 + √(9M ÷ 10P)), 9 × (100 + MR) × (1 + √(10P ÷ 9M)) } -3800), which you can either use to increase your health, magic resistance or armor, the way to maximize your effective health is to spend gold on your health until both your health ≥ 7.5 × (100 + armor) × (1 + √(9M ÷ 10P)) = 7.5 × (0 + 100) × (1 + √(9M ÷ 10P)) = 750 × (1 + √(9M ÷ 10P)) and health ≥ 6.75 × (100 + MR) × (1 + √(10P ÷ 9M)) = 6.75 × (0 + 100) × (1 + √(10P ÷ 9M)) = 675 × (1 + √(10P ÷ 9M)), then increase either MR or armor, depending on which of the two inequalities is still strict, until both inequations reach equality. In that moment you achieved equilibrium, but with still some unused gold. Lastly, you split the remaining gold in half, spend half on your health and divide the remaining gold between your armor and magic resistance by ratio √10P : √9M, respectively (as gold values of these stats have ratios 1 : 7.5 : 6.75, respectively, it would lead to buying additional health, armor and magic resistance proportionally with ratios (√10P + √9M) : (√10P ÷ 7.5) : (√9M ÷ 6.75), respectively, increasing all sides of equations above by same amount and thus naturally preserving the equalities).

Note: One can notice that if one damage type component becomes too small relatively to other, either P ÷ M or its inverse will gain increasingly large values. Both fractions are occuring in above inequations. As a result, if this happens, then minimum gold and minimum equilibrium health requirements might very swiftly skyrocket into really large numbers, to such extent that equilibrium line becomes unreachable and practically unusable. Similarly, this article deals with mixed effective health, so naturally neither its physical damage nor magic damage are supposed to be zeros (and some results cannot be applied). If any damage type component represents a very small fraction of total damage, including 0%, it is more appropriate to apply basic equilibrium lines for either physical effective health or magical effective health.

Now we just formulated a 'rule of preserving equilibrium (or maximum effective health)':

Once equilibrium state is reached, all we need to do to preserve it is to always distribute gold into health, armor and magic resistance with ratios (√10P + √9M) : √10P : √9M, respectively, for the rest of the game.

... or in other words, always 50% gold into health and remaining 50% gold into armor with magic resistance.

Again, this model is highly simplified and cannot be exactly applied in cases when we are buying any other items than basic armor item, Chain Vest, basic magic resistance item, Negatron Cloak or basic health item (for example if our decision-making process would involve Giant's Belt instead of Ruby Crystal, the above model would need to use equilibrium constants 7.6 and 6.84). Even considering the purchase of different health, armor or magic resistance items with differing gold efficiencies (quite natural expectation under real circumstances) makes use of single constant utterly impossible. Going even further, the continuous model simplifies a discrete character of real shopping, as you cannot really buy 1.5 × Ruby Crystals for 600, so with that much gold you opt to buy either a single Ruby Crystal or 2 × Cloth Armors or a single Null-Magic Mantle, drastically changing the equilibrium constants to 5.0 and 6.0.

Thankfully to almost linear item stats' gold efficiency a player could use weakened base equilibrium conditions in a form: 7.5 × (100 + armor) ÷ √10P ≈ HP ÷ (√10P + √9M) ≈ 6.75 × (100 + MR) ÷ √9M to objectively access own decision-making without need to hold to equalities too strictly. However, the presence of square roots in the formulae makes real-time manual use of such conditions highly impractical. To make the formula as easy to apply as possible, we can use the following simplified ratio form:

$\pagecolor {Black}\color {White}(100+{\it {armor}}):{\it {HP}}:(100+{\it {MR}})\approx {\sqrt {P}}:7({\sqrt {P}}+{\sqrt {M}}):{\sqrt {M}}$

The equations still can be practically used for the purpose of pre-game analysis. Let us suppose that a bulk (or any champion intending to buy 6 mainly defensive items) has to face a team of 5 enemy champions, with all 5 being equally potent in damage. Depending on enemy team combination of AD/AP champions (let us suppose that we are dealing with clear damage archetypes), the bulk's optimal decision-making between buying armor and MR might follow this pattern if we apply the square root proportionality (HP can be also treated in similar fashion, but now we will omit it for the sake of transparency):

5 AD & 0 AP → 100 armor : 0 MR → 6 armor items, 0 MR items
4 AD & 1 AP → 65 armor : 35 MR → 4 armor items, 2 MR items
3 AD & 2 AP → 54 armor : 46 MR → 3 armor items, 3 MR items
2 AD & 3 AP → 44 armor : 56 MR → 3 armor items, 3 MR items
1 AD & 4 AP → 32 armor : 68 MR → 2 armor items, 4 MR items
0 AD & 5 AP → 0 armor : 100 MR → 0 armor items, 6 MR items

Two facts are immediately observable from the list. The first is that seemingly quite unequal team composition of 2 enemy champions of one damage type and 3 of the other type induces need to invest the very equal shares into both resists. The second observation is that a presence of a single champion of a complementary damage in otherwise full AD/AP team stimulates enemy bulks to optimally put entire one third of own resists into the secondary resist. This is a strong contributing factor behind the idea of AD/AP carries as a single champion of differing damage type in a team greatly enhances enemy's requirement to invest own resources into the corresponding resist, a gold that they could otherwise freely invest into more single-purpose focused stats.

Intuition could mislead a player to expect that only a little armor/magic resistance (in case of bulk, a single item) would suffice against almost pure AD/AP team, respectively. The analysis of effective health shows, however, that such premise is wrongly based on assuptions of linear proportionalities between offensive and defensive stats which, although true, do not carry over this particular problem. As a result, a team underestimation of one resist's necessity, armor or magic resistance, indirectly amplifies the damage output effectivity of the only AD/AP opponent and potentially leads to him/her snowballing, thus effectively becoming a carry with less effort. To put it very simply, square root proportionality results in optimal defense ratio of approximately 1:2 when being confronted by mixed damage with ratio of 1:4. Building resists with ratio 1:4 leads to taking mixed damage with ratio 1:1, allowing a single enemy champion to deal 50% of overall damage to bulks.

The above analysis doesn't entirely apply to squishy champions. Such champions usually have very low resists and thus hidden values of +100 armor and +100 MR in equilibrium conditions are much more impactful. As a result, the squishy's optimal decision-making between resists might follow a bit different pattern:

5 AD & 0 AP → 1 armor item, 1 armor(&HP) item (HP won't scale enough just from levels)
4 AD & 1 AP → 1 armor and/or HP item (armor from leveling is sufficient, both stats can help)
3 AD & 2 AP → 1 HP item (more than enough resists but deficient HP)
2 AD & 3 AP → 1 HP item
1 AD & 4 AP → 1 MR item
0 AD & 5 AP → 2-3 MR items (squishies have naturally low innate MR)

However, carry champions are logically focusing on damage output rather than optimizing own resists and usually tend to deviate a lot more often from the pattern, instead opting for defense items with interesting uniques such as Zhonya's Hourglass, Mercurial Scimitar, Guardian Angel or Hextech Protobelt-01.

Example: Player's kill recap screen shows that the fatal damage was composed of 66% physical damage and 33% magic damage, hence composition ratio of the lethal mixed damage was cca. 1:2. The appropriate resists' combination to withstand it should therefore head towards ratio of cca. √0.5 ≈ 2:3. However, when distributing resists, player has to calculate with +100 armor and +100 MR more than he actually has in stats.

This information is strongly theoretical and due to game limitations from champions' base stats, innate abilities and non-linearity of gold value of item stats (gold value of stats differs for different items or is even impossible to be objectively evaluated due to interference of unique item abilities), the real equilibrium function is too complicated to be any useful. Furthermore, compactibility of game items, as well as limit of 6 regular item slots and one trinket slot, makes application of balance function poorly executable.

The complexity of this problem provides space for players' intuition to develop and demonstrate their itemization skills. If given sufficient amount of time, each player could perfectly analyze situation at any given moment when he exited the shop and tell what should he buy at that moment for available gold to maximize own effective health. The sheer impossibility of doing such thing in real time creates opportunity to develop the skill. Not only that but often choosing to maximize current effective health leads to suboptimal decision branches in the future. The summary on end game screen about type of fatal damage taken is a key part of this decision process as well.

Instead, broadly speaking, items which provide multiple defense stats, give a very high amount of effective health compared to items which only provide pure single stat. These items should be purchased when a player is seeking efficient ways to reduce the damage they take by a large amount. Furthermore, these items are among all available items the best ones to distribute their gold value more equally among health, armor and magic resistance, thus working better for rule of preserving equilibrium.

Health as a casting resource

Main article: Manaless

A few champions also use their own health to cast abilities instead of mana:

Other champions' abilities

Olaf's Reckless Swing costs 21 / 34.5 / 48 / 61.5 / 75 (+ 12% AD) health per use.
Soraka's Astral Infusion costs 10% of her maximum health and 40 / 45 / 50 / 55 / 60 mana per use.

Health as scaling

Personal health

These use the champion's personal health pool to increase the magnitude of the ability. It could involve total health or bonus health. By building health items you can receive more benefit and power from these abilities in most situations.

Azir's Shifting Sands grants him a shield that blocks for 15% of his bonus health damage.
Braum's Winter's Bite deals magic damage equal to 70 / 115 / 160 / 205 / 250 (+ 2.5% of maximum health).
Darius' Decimate heals him for 12% of his missing health for every enemy champion hit by the Blade, up to 36% of his missing health.
Dr. Mundo's Adrenaline Rush receives bonus health regeneration per second equal to 0.3% of his maximum health.
- Dr. Mundo's Masochism increases his attack damage by 40 / 55 / 70 / 85 / 100, increased by 1% for every 1% of his missing health.
- Dr. Mundo's Masochism next attack deals bonus physical damage equals to 3 / 3.5 / 4 / 4.5 / 5% of his health.
- Dr. Mundo's Sadism heals 40 / 50 / 60% of his maximum health over 12 seconds.
Gangplank's Remove Scurvy heals him for 50 / 75 / 100 / 125 / 150 (+ 15% of his missing health) (+ 90% AP).
Garen's Perseverance regenerates Error: Parameter '3' is not accepted.% of his maximum health per second if he has not been hit with an enemy ability or taken damage from any source (excluding minions) in the last Error: Parameter '3' is not accepted. seconds.
Gragas' Happy Hour heals 4% of his maximum health instantly every time he uses an ability (8 second cooldown).
Gnar's Hop deals physical damage equal to 20 / 60 / 100 / 140 / 180 (+ 6% of his maximum health).
Illaoi's Tentacle Smash makes her tentacle heals her for 5% of her missing health if it hits at least one champion.
Karma's Renewal heals herself for 20% (+ 1% per 100 AP) of her missing health when she is tethered to the enemy champion, and another 20% (+ 1% per 100 AP) of her missing health if the tether persists for the whole duration.
Kled's Skaarl the Cowardly Lizard makes 100% of his bonus health apply to Skaarl instead.
Lissandra's Frozen Tomb heals her for 100 / 150 / 200 (+ 30% AP), increased by 1% for every 1% of her missing health.
Malphite's Granite Shield grants him a shield equal to 10% of his maximum health which recharges if he hasn't been damaged for Error: Parameter '3' is not accepted. seconds.
Maokai's Sap Magic heals Error: Parameter '3' is not accepted.% of his maximum health when he attacks with 5 magical sap stacks.
Master Yi's Meditate heals him for 30 / 50 / 70 / 90 / 110 (+ 15% AP), increased by 1% for every 1% of his missing health.
Mordekaiser's Iron Man shields him for up to 25% of his maximum health.
Nautilus' Titan's Wrath grants him a shield that blocks for 65 / 70 / 75 / 80 / 85 (+ 9 / 11 / 13 / 15 / 17% of maximum health).
Nunu's Consume on a large monster grants him 2% maximum health, stacking up to 5 times for a maximum of 10% maximum health.
Olaf's Berserker Rage increases his attack speed by 1% for every 1% of his missing health.
- Olaf's Vicious Strikes provides 0.5% enhanced healing from all sources for every 1% missing health.
Poppy's Iron Ambassador grants her a shield upon picking up the buckler that blocks for 15 / 17.5 / 20% of her maximum health.
Rengar's Empowered Battle Roar Empowered Battle Roar heals him for 8 + (4 × level), increased by 6.25% (+ 1% of his missing health).
Sejuani's Flail of the Northern Winds deals 40 / 70 / 100 / 130 / 160 (+ 4 / 6 / 8 / 10 / 12% of maximum health) (+ 60% AP) magic damage over 4 seconds.
Shen's Ki Barrier shields himself from Template:Pp18 (+ 14% bonus health) damage for 2.5 seconds after using an ability.
- Shen's Shadow Dash deals physical damage equal to 50 / 75 / 100 / 125 / 150 (+ 12% bonus health).
Sion's Soul Furnace shields him for up to 30 / 55 / 80 / 105 / 130 (+ 6 / 7 / 8 / 9 / 10% of maximum health) (+ 40% AP) for up to 6 seconds.
Skarner's Crystalline Exoskeleton shields him for up to 10 / 11 / 12 / 13 / 14% of his maximum health (+ 80% AP) for 6 seconds.
Sona's Aria of Perseverance heals her for 30 / 50 / 70 / 90 / 110 (+ 20% AP), increased by 0.5% for every 1% of her missing health.
Soraka's Starcall heals her for 25 / 35 / 45 / 55 / 65 (+ 40% AP) for every enemy champion hit, increased by 1% for every 1% of her missing health.
Tahm Kench's An Acquired Taste makes his autoattacks and abilities deal Error: Parameter '3' is not accepted.% of his maximum health as bonus magic damage, stacking up to 3 times for a maximum bonus damage of Error: Parameter '3' is not accepted.% of his maximum health.
Taric's Starlight's Touch restores 20 / 30 / 40 / 50 / 60 (+ 20% AP) (+ 1.5% bonus health) health per charge up to maximum of 3 charges per cast, to himself and all nearby allied champions.
- Taric's Bastion shields himself and a target allied champion for 8 / 9 / 10 / 11 / 12% of the targets maximum health damage for up to 2.5 seconds.
Tryndamere's Bloodlust increases his attack damage by 5 / 10 / 15 / 20 / 25 (+ 0.15 / 0.2 / 0.25 / 0.3 / 0.35 per 1% of missing health).
Vladimir's Crimson Pact increases his ability power by 2.5% of his bonus health.
- Vladimir's Sanguine Pool deals 80 / 135 / 190 / 245 / 300 (+ 10% of bonus health) magic damage over 2 seconds.
- Vladimir's Tides of Blood deals 30 / 45 / 60 / 75 / 90 (+ 2.5% of bonus health) (+ 35% AP) to 60 / 90 / 120 / 150 / 180 (+ 10% of bonus health) (+ 70% AP) magic damage based on how long he charges it.
Vi's Blast Shield gives her a shield equal to 10% of her maximum health when she hits an enemy with one of her activated abilities with a cooldown of Error: Parameter '3' is not accepted. seconds.
Volibear's Chosen of the Storm heals 30% of his maximum health over 6 seconds if he gets under 30% health.
- Volibear's Frenzy deals 80 / 125 / 170 / 215 / 260 (+ 15% of bonus health) as physical damage.
Zac's Cell Division sheds a chunk of himself each time he hits an enemy with an ability that can be reabsorbed to restore 4% of his maximum health. Upon taking fatal damage, Zac splits into 4 Bloblets that attempt to recombine. Each Bloblet has 12% of Zac's maximum health.

Scaling from enemy health

Maximum health

These abilities grant extra damage based on the target's maximum health. Typically, the more maximum health the target has, the more damage these abilities will deal. Therefore, they are more powerful against high-health targets, but their effect against low-health targets should not be ignored. Also note this type of extra damage is always capped against minions and monsters to prevent players dealing massive damage to high health pool monsters like Template:Moi.

Amumu's Despair harms nearby enemies for 8 / 12 / 16 / 20 / 24 (+ 1 / 1.5 / 2 / 2.5 / 3% (+ 1% per 100 AP) of their maximum health) magic damage per second.
Brand's Blaze causes his spells to debuffs the target, dealing 2% of their maximum health each second as magic damage for 4 seconds, capping at 80 against monsters.
Fiora's Duelist's Dance, against Vitals, deals 2% (+ 4.5% per 100 bonus AD) of target's maximum health bonus true damage.
Gnar's Hyper deals 10 / 20 / 30 / 40 / 50 (+ 100% AP) (+ 6 / 8 / 10 / 12 / 14 % of target's maximum health) as magic damage each 3 hits or spells, capping at 100 / 150 / 200 / 250 / 300 against monsters.
Gragas' Drunken Rage deals 20 / 50 / 80 / 110 / 140 (+ 30% AP) (+ 8% of the target's maximum health) magic damage, capping at 300 against monsters.
Garen's Demacian Justice makes the enemy champion with the most recent kills the Villain. Garen's basic attacks and ticks of Judgment deal 1% target's maximum health as bonus true damage versus Villains.
Jayce's Thundering Blow deals (8 / 10.4 / 12.8 / 15.2 / 17.6 / 20% of the target's maximum health) (+ 100% bonus AD) as bonus magic damage, capping at 200 / 300 / 400 / 500 / 600 / 700 against monsters.
Kalista's Sentinel deals 10 / 12.5 / 15 / 17.5 / 20% of the target's maximum health as magic damage, capping at 75 / 125 / 150 / 175 / 200 against monsters.
Kindred's Mounting Dread deals 80 / 110 / 140 / 170 / 200 (+ 20% AD) (+ 5% of the target's maximum health) bonus physical damage on the third autoattack upon the crippled target.
Kled's Violent Tendencies buffs his next 4 basic attacks, with the final attack dealing 20 / 30 / 40 / 50 / 60 (+ 4 / 5 / 6 / 7 / 8% of the target's maximum health) bonus physical damage.
- Kled's Chaaaaaaaarge!!! makes Kled and Skaarl charge toward a target location, ramming into the nearest enemy champion, dealing up to 12 / 15 / 18% (+ 12% per 100 AD) of the target's maximum health.
Kog'Maw's Bio-Arcane Barrage gives him a temporary buff to his autoattacks dealing 2% (+ 0.75% per 100 AP) of the target's maximum health as bonus magic damage, capping at 100 against minions and monsters.
- Kog'Maw's Living Artillery deals 140 / 220 / 300 (+ 130% bonus AD) (+ 50% AP) magic damage against enemies below 50% health and 210 / 330 / 450 (+ 195% bonus AD) (+ 75% AP) magic damage against enemies below 25% health.
Malzahar's Nether Grasp creates a zone underneath his target that harms enemies standing on it for 5 / 7 / 9% (+ 1.5% per 100 AP) of their maximum health as magic damage per second, capping at 120 against minions and monsters.
Maokai's Twisted Advance transforms him into a cloud of arcane energy that quickly travels to a target enemy, dealing 9 / 10 / 11 / 12 / 13% (+ 3% per 100 AP) of target's maximum health magic damage, capping at 300 against minions and monsters.
Mordekaiser's Children of the Grave deals to an enemy champion 25 / 30 / 35% (+ 4% per 100 AP) of the target's maximum health as magic damage to the target, dealing 25% of the damage initially and 75% over 10 seconds.
Nasus' Fury of the Sands empowers him for 15 seconds, dealing 3 / 4 / 5% (+ 1% per 100 AP) of nearby enemies maximum health magic damage per second for the duration, capping at 240 magic damage per second per enemy.
Pantheon's Certain Death causes his autoattacks and Spear Shot to automatically critically strike enemies below 15% health.
Poppy's Hammer Shock deals 35 / 55 / 75 / 95 / 115 (+ 80% bonus AD) (+ 7% of target's maximum health) physical damage in an area and creates a zone that slows, then explodes after 1 second, dealing the same damage again.
Sejuani's Flail of the Northern Winds deals 4 / 4.5 / 5 / 5.5 / 6% (+ 3% per 100 AP) of the target's maximum health bonus magic damage on her next basic attack. Upon attacking or reactivating, Sejuani deals 10 / 17.5 / 25 / 32.5 / 40 (+ 1 / 1.5 / 2 / 2.5 / 3% of the target's maximum health) (+ 15% AP) magic damage around her per second for 4 seconds.
Shen's Twilight Assault makes his next 3 basic attacks within 8 seconds deal magic damage equal to 3 / 3.5 / 4 / 4.5 / 5% (+ 1.5% per 100 AP) of target's maximum health in a zone near to Spirit Blade; if the spirit blade collides with an enemy champion, the empowerment is enhanced, dealing 2% (+ 0.5% per 100 AP) of target's maximum health bonus magic damage and gain 50% bonus attack speed.
Shyvana's Flame Breath hits enemies and marks them. Shyvana's basic attacks against marked enemies deal 2.5% of their maximum health bonus magic damage, capping at 100 against monsters.
Singed's Fling deals 50 / 65 / 80 / 95 / 110 (+ 6 / 6.5 / 7 / 7.5 / 8% of target's maximum health) (+ 75% AP) magic damage, capped at 300 against minions and monsters.
Sion's Glory in Death makes his auto attacks deal 10% of target's maximum health as physical damage, capping at 75 bonus physical damage against minions and monsters.
- Sion's Soul Furnace deals 40 / 65 / 90 / 115 / 140 (+ 40% AP) (+ 10 / 11 / 12 / 13 / 14% of target's maximum health) as magic damage. The health percent of the target damage is capped at 400 against minions and monsters.
Tahm Kench's Regurgitate deals 20 / 23 / 26 / 29 / 32% (+ 2% per 100 AP) of the target's maximum health magic damage, capped at 400 / 450 / 500 / 550 / 600 against monsters.
Trundle's Subjugate drains instantly to an enemy champion 10 / 13.75 / 17.5% (+ 1% per 100 AP) of the target's maximum health magic damage, and the same amount over 4 seconds.
Varus' Blighted Quiver adds marks through auto attacks which can be detonated via any of his other spells for 2 / 2.75 / 3.5 / 4.25 / 5% (+ 2% per 100 AP) of the target's maximum health magic damage per mark. Maximum 3 marks for 6 / 8.25 / 10.5 / 12.75 / 15% (+ 6% per 100 AP) of the target's maximum health magic damage, capping at 360 against monsters.
Vayne's Silver Bolts adds marks after each spell or auto attack on her target. After 3 of these marks, the affected target will suffer (6 / 7.5 / 9 / 10.5 / 12% of the target's maximum health) true damage, with a minimum damage of 40 / 60 / 80 / 100 / 120, and capping at 200 against monsters.
Vi's Denting Blows deals 4 / 5.5 / 7 / 8.5 / 10% (+ 1% per 35 bonus AD) of the target's maximum health additional physical damage on every 3rd attack on the same target, capping at 300 against minions and monsters.
Warwick's Hungering Strike deals 75 / 125 / 175 / 225 / 275 (+ 100% AP) magic damage or 8 / 10 / 12 / 14 / 16% of the target's maximum health (+ 100% AP) magic damage (whichever is higher).
Yorick's Eulogy of the Isles causes his basic attacks to deal Error: Parameter '3' is not accepted.% of the target's maximum health bonus magic damage against enemies targeted by the Maiden of the Mist.
Zac's Unstable Matter deals 40 / 55 / 70 / 85 / 100 (+ 4 / 5 / 6 / 7 / 8% (+ 2% per 100 AP) of enemies' maximum health) magic damage to all nearby enemies. The health percent of the target damage is capped at 200 against minions and monsters.
Zed's Contempt for the Weak causes his basic attack to deal Error: Parameter '3' is not accepted.% of the target's maximum health bonus magic damage whenever the target is below 50% health.

Current health

These abilities grant extra damage based on the target's current health. Typically, the more current health the target has, the more damage these abilities will deal. Building additional max health can reduce the effect of skills based on current health over a long fight, but has quickly diminshing returns.

Dr. Mundo's Infected Cleaver deals 80 / 130 / 180 / 230 / 280 magic damage or 15 / 17.5 / 21 / 22.5 / 25% of the target's current health magic damage (whichever is higher), capping at 300 / 350 / 400 / 450 / 500 against minions and monsters.
Elise's Neurotoxin deals 40 / 75 / 110 / 145 / 180 (+ 4% (+ 3% per 100 AP) of the target's current health) magic damage. The percent health is capped at 75 / 100 / 125 / 150 / 175 against monsters.
Evelynn's Agony's Embrace impales all enemy champions in the targeted area, dealing 15 / 20 / 25% (+ 1% per 100 AP) of enemies' current health magic damage.
Jarvan IV's Martial Cadence causes his first attack on a target to deal 10% of their current health bonus physical damage, capping at 400.
Kindred's Mark of the Kindred causes Lamb's auto-attacks to deal 1.25% of their current health bonus physical damage per stack, capped at 75 + (10 per stack) against monsters.
Xin Zhao's Crescent Sweep deals 75 / 175 / 275 (+ 100% bonus AD) (+ 15% of enemies' current health) physical damage to all nearby enemies. The health percent of the enemies' hit is capped at 600 against monsters.
Yorick's Mourning Mist deals 15% of target's current health as magic damage to all enemies hit in an area, with a minimum damage of 70 / 105 / 140 / 175 / 210 magic damage.

Missing health

These abilities grant extra damage based on the target's missing health. The less current health the target has (can be either a flat or percentage amount), the more damage these abilities will deal. These are often referred as "execute" abilities, as they work best on nearly dead targets.

Ekko's Parallel Convergence passively makes Ekko's basic attacks deal 5% 「 (+ 2.22% per 100 AP) 」「 (+ 1% per 45 AP) 」 of target's missing health bonus magic damage versus targets below 30% of their maximum health, capping at 150 against minions and monsters.
Elise's Venomous Bite deals 60 / 100 / 140 / 180 / 220 (+ 8% (+ 3% per 100 AP) of the target's missing health) magic damage. The percent health is capped at 75 / 100 / 125 / 150 / 175 against monsters.
Fizz's Seastone Trident passively makes Fizz's basic attacks deal 20 / 30 / 40 / 50 / 60 (+ 45% AP) (+ 4 / 5 / 6 / 7 / 8% of the target's missing health) magic damage on-hit over 3 seconds.
Garen's Demacian Justice deals to an enemy champion 175 / 350 / 525 (+ 28.57 / 33.33 / 40% of the target's missing health) magic damage.
Jhin's Whisper deals Error: Parameter '3' is not accepted.% of target's missing health bonus physical damage each 4 shots.
- Jhin's Curtain Call deals 50 / 125 / 200 (+ 25% AD) physical damage, increased by 2% for every 1% of the target's missing health.
Jinx's Super Mega Death Rocket! deals between 25 / 35 / 45 (+ 10% bonus AD) (+ 25 / 30 / 35% of the target missing health) and 250 / 350 / 450 (+ 100% bonus AD) (+ 25 / 30 / 35% of the target's missing health). The percent health of the target is capped at 300 against minions and monsters.
Lee Sin's Resonating Strike deals 50 / 80 / 110 / 140 / 170 (+ 90% bonus AD) (+ 8% of target's missing health) physical damage, capping at 400 against minions and monsters.
Morgana's Tormented Soil deals 0.5% increased damage for every 1% of the target's missing health. Going from 16 / 32 / 48 / 64 / 80 (+ 22% AP) to 24 / 48 / 72 / 96 / 120 (+ 33% AP) magic damage per second for 5 seconds.
Nidalee's Takedown deals 1 / 1.25 / 1.5 / 1.75% increased damage for every 1% of the target's missing health, capping at 150% increased damage. Going from 4 / 20 / 50 / 90 (+ 75% AD) (+ 36% AP) to 10 / 50 / 125 / 225 (+ 187.5% AD) (+ 90% AP) magic damage.
Riven's Wind Slash deals 2.67% increased damage for every 1% of an enemy's missing health, capping at 200% increased damage (at about 74.9% missing health). Going from 80 / 120 / 160 (+ 60% bonus AD) physical damage to 240 / 360 / 480 (+ 180% bonus AD) physical damage.
Volibear's Frenzy deals 1% increased damage for every 1% of the target's missing health, capping at 100% increased damage. Going from 80 / 125 / 170 / 215 / 260 (+ 15% of bonus health) physical damage to 160 / 250 / 340 / 430 / 520 (+ 30% of bonus health) physical damage.

Bonus health

These abilities grant extra damage based on the target's bonus health. Typically, the more bonus health the target has, the more damage these abilities will deal. Therefore, they are more powerful against tanks with a lot of health.

Lee Sin's Dragon's Rage deals 200 / 400 / 600 (+ 200% bonus AD) (+ 12 / 15 / 18% of kicked target's bonus health) physical damage to all enemies that the target collides with.
Mordekaiser's Children of the Grave grants Mordekaiser 25% of target's bonus health while the ghost is active.

Items

Blade of the Ruined King: Passive: Unique – Clawing Shadows: Your next basic attack on-hit against an enemy champion is empowered to slow them by ( 30% / 15%) for 1 second (15 second cooldown).
Face of the Mountain: Active: Unique – Deadly Phalanx: Shield yourself and an ally equal to 10% of your maximum health for 4 seconds. Afterwards, the shield is consumed to slow nearby enemies by 40% for 2 seconds (60 second cooldown).
Liandry's Torment: Passive: Unique – Suffering: For each second in combat with enemy champions, deal 2% increased damage, stacking up to 3 times for a total of 6%.
Sterak's Gage: Passive: Unique – The Claws that Catch: Gain bonus attack damage equal to 50% base AD. Passive: Unique – Lifeline: If you would take damage that would reduce you below 30% of your maximum health, you first gain a shield that absorbs damage equal to 80% of bonus health which decays over 4.5 seconds, as well as 10% increased size for 8 seconds (60 second cooldown).
Warmog's Armor: Passive: Unique: Grants Warmog's Heart if you have at least 1300 bonus health. Passive: Unique – Warmog's Heart: Regenerate「 2.5% maximum health every 0.5 seconds 」「 25% maximum health every 5 seconds 」and gain 10% bonus movement speed if damage has not been taken in the last 6 seconds (3 seconds for damage from non-champions).
Zz'Rot Portal: Active: Unique: Spawns a Void Gate at the target location for 120 seconds. Every 4 seconds the gate summons a Voidspawn that travels down the nearest lane and decays in health over time. The Voidspawn explodes upon attacking structures. Voidspawn do not attack enemy champions nor void targets. The first and every fourth Voidspawn deals damage equal to 15% of your maximum health (120 second cooldown).

Masteries

Courage of the Colossus: Gain a shield for 3 − 54 (based on level) (+ 5% maximum health) per nearby enemy champion for 3 seconds after hitting an enemy champion with a stun, taunt, snare, or knock up. (45 − 30 (based on level) second cooldown)
Greenfather's Gift: Stepping into brush causes your next attack or damaging ability to deal (3% of target's current health) bonus magic damage. (9 second cooldown)

Ways to restore health

Main article: Health regeneration

A champion's health can be restored in several ways:

By the health regeneration.
Using a Health Potion, Total Biscuit of Rejuvenation, Refillable Potion, Hunter's Potion, or Corrupting Potion.
Returning to the spawning pool, which restores a percentage of your maximum health per second.
Leveling up will restore some maximum health, and some current health. Actual health regained is lower depending on how wounded the champion is upon leveling up.
Smiting the Red Brambleback Red Brambleback (restores instantly 20% of maximum health).
Having the Crest of Cinders buff, which can be obtained by slaying the Red Brambleback Red Brambleback or by slaying an enemy champion that has the buff (restores 1% maximum health per 5 seconds).
Slaying a monster that has Healing Sigil (Template:Moi, Template:Moi, Template:Moi, Template:Moi and Template:Moi).
Killing a unit while having Feast mastery active.
Obtaining kill or assist while having Dangerous Game mastery active (restores instantly 5% of missing health).
By using life steal, dealing damage with basic attacks will restore health.
By using Death's Dance, dealing physical damage will restore health.
By using spell vamp, dealing damage with abilities will restore health.
By using Hextech Gunblade, dealing damage will restore health.
The passive effect of Catalyst the Protector, Hextech GLP-800, Rod of Ages and Righteous Glory restores 20% of mana as health per cast (max 15 health) or per second for toggle spells (max 15 health per second).
Using a healing ability or spell, such as Soraka's Astral Infusion, Nami's Ebb and Flow, or Heal.

Ways to modify health restoration

There are multiple ways how to modify magnitude of health restoration (including healing, life steal, spell vamp, Death's Dance's passive, Hextech Gunblade's passive and health regeneration). Health gain effects such as Lulu's Wild Growth are not considered to be health restoration effects and as such remain unaffected.

Decreasing health restoration

A champion's health restoration can be reduced in following ways (the list does not include internal spell mechanics or scalings):

Grievous Wounds debuff reduces all health restoration on target by 40%.
Murder Bridge map reduces all outsourced health restoration by 50%.

Increasing health restoration

A champion's health restoration can be amplified in several ways (the list does not include internal spell mechanics or scalings as well as secondary healing by allies):

Champion abilities

Olaf's Vicious Strikes increases own health restoration by 0.5% per 1% of his missing health.
Trundle's Frozen Domain increases own health restoration by 20%.