A champion statistic is a number indicating how well a champion can do a certain thing. These help define the assets of a champion. There are 24 statistics, divided into 4 categories: Offensive, Defensive, Utility and Other.
Contents
Offensive
 Ability power: Provides scaling on some abilities.
 Armor penetration: How much the armor values of targets are reduced during physical damage calculations.
 Attack damage: Provides the initial damage value of basic attacks and scaling on some abilities.
 Attack speed: The rate at which a champion uses their basic attack and scaling a few abilities.
 Critical strike chance: The percent chance that a basic attack will critically strike to deal increased damage.
 Critical strike damage: The percentage damage increase provided by critical strike chance.
 Life steal: The percentage of the damage done by a champion's basic attacks that is returned to them as health.
 Magic penetration: How much the magic resistance values of targets are reduced during magic damage calculations.
 Omnivamp: The percentage of the damage done by a champion that is returned to them as health.
 Physical vamp: The percentage of the physical damage done by a champion that is returned to them as health.
Defensive
 Armor: Used to calculate the reduced damage (in percentage) taken from basic attacks and abilities that deal physical damage. Calculated by armor ÷ (armor + 100)
 Heal and shield power: Increases the strength of heals and shields.
 Health: The total damage a champion may take before dying.
 Health regeneration: The rate at which a champion's health is naturally restored.
 Magic resistance: Used to calculate the reduced damage (in percentage) taken from abilities that deal magic damage. Calculated by MR ÷ (MR + 100).
 Tenacity: Measured in percentages of how much the duration of most disables will be reduced.
 Slow resist: Measured in percentages of how much the strength of slows will be reduced.
Utility
 Ability haste: Reduces the time after an ability is used by a champion before it can be used again.
 Energy: The maximum energy available to a champion for casting abilities.
 Energy regeneration: The rate at which a champion's energy is naturally restored.
 Mana: The maximum mana available to a champion for casting abilities.
 Mana regeneration: The rate at which a champion's mana is naturally restored.
Other
 Experience: The way champions level up periodically.
 Gold generation: The rate of passive gold income.
 Movement speed: The speed at which a champion moves around the map.
 Range: Measurement used to determine how far an autoattack or ability can reach (referred to as attack range or ability range respectively).
Increasing Statistics
"Time for a shakedown."

All champions begin the game with a certain amount of attack damage, attack speed, armor, magic resistance, health, health regeneration, resource or mana, and resource or mana regeneration. This is called the base value of that statistic. All champions naturally increase these stats by a nonlinear amount every time they gain a level.
All champions have the same formula for calculating their statistics (see below). Obviously, all champions go through the same 18 levels during the game. However, each champion and skill has a different growth statistic. For example, the AD growth statistic for is 3.375, but his mana growth statistic is 45. has AD and mana growth statistics of 2.41 and 40, which are different than . Currently, is the only champion who can modify his growth statistics. All other champions have fixed growth statistics.
 b = base
 g = growth statistic
 n = champion level
 (n  1) = total amount of level ups
For example, health (health base statistic), and his health growth statistic is 106. At level 2, the equation shows that his total health is 689.68 displayed in game as a rounded value 690 (n = 2, g = 106, and b= 613.36).
starts level 1 with 613.36Importantly, each champion's base statistics and growth statistics are unique. This makes a big difference on the battlefield. If a champion has low base statistics but high growth statistics, they will be weak at the game's beginning but strong at the game's end.
Five statistics that deviate from this pattern are critical strike damage, range, experience, gold generation and movement speed. All champions start with 175% base critical damage (even , and despite their innate passives). All champions start the game with the same Gold generation and need the same amount of experience to level up. Every champion has unique base range and movement speed that do not increase naturally. Natural increase is meant to be as from leveling up itself, innate passives as or , despite being perlevel innates, are not considered to be natural stat increases.
All other statistics have a natural value of zero and must be increased by other sources. The ways a champion may increase their statistics are varied and include runes, items, and auras. Some champion abilities increase that champion's statistics, either as a passive effect ( passively increases his life steal) or as an active effect ( briefly increases his armor and MR) or as an effect that follows another action ( , for example, passively increases his attack speed and doubles this bonus when he absorbs a spell).
Growth statistic calculations
Since patch V4.20, champions do not gain stats linearly with levels. Instead, their increase in strength stats accelerates at higher levels. The above equation can be rearranged to:
 g = growth statistic
health is 100. When levelingup from level 1 to level 2, the number in the brackets becomes 0.72 (or 72%) and her total health will increase by 72 (g = 100 and NewLevel = 2). To explain it another way, her growth statistic (100) was multiplied by 72% giving 72 health. However, when levelingup from 15 to 16, the percent increase is 121% and the health increase is much higher at 121 health (g = 100 and NewLevel = 16).
growth statistic forAt level 18, the champion will have accumulated 1700% of the growth stats (17 × growth stats), so she ends with 17 × growth stats + base stats.
Notes
 As of patch V4.20, champion statistics such as health, attack damage, etc. are listed as having a given base value. This is the value at Level 1.^{[1]} (You can also verify this yourself by entering a game with no runes and viewing your champion statistics).
 Any unit's attack damage, ability power, armor, magic resistance, attack speed, movement speed, ability haste and critical strike chance, can be seen by selecting that unit in game, along with two bars indicating their current and maximum health and mana (or equivalent resource).
 Player's health regeneration, mana regeneration, armor penetration, magic penetration, life steal, physical vamp, omnivamp, attack range, and Tenacity can be additionally seen by opening advanced player stats (default binding to C).
 Gold generation and Heal and shield power must be calculated by the player during the game.
 If the value is written in white, that unit has only the base amount of that statistic. If the value is written in bold yellow, that statistic has been increased from the base amount through external means. By hovering the cursor over almost any stat the base amount is displayed in tooltip in blue plus bonus amount in green. The total of stat is either blue if there is no bonus amount, or green. This applies to all visible stats with exception of penetrations, health and resource bar.
 If the total value of stat is written in bold yellow, but in blue in tooltip, then the stat has not been really increased, just displayed as rounded up. This also doesn't apply to penetration stats, health and resource bar.
 Hovering the cursor over health and resource bar additionally displays values of health and resource regeneration in respective base units per second while hovering over regeneration stats themselves in the stat table displays values in traditional base units per 5 seconds.
 Armor penetration and magic penetration use own unique format 'F  P%', where F shows flat penetration and P percentage penetration in percent. All four values are always written in blue regardless of being externally modified or not (as all champions have base penetration values of 0, the color exception is purely aesthetical).
 Armor and magic resistance also include the resulting damage reduction in own tooltips.
 Total critical damage is not shown in the player stats in game. However, base critical damage is misleadingly displayed as base critical damage bonus in tooltip of Critical Strike with literal value of 175%.
Infinite stat stacking
The following 8 champions can stack a stat infinitely:
, , , , , , , .See also
References
Offensive  Ability power · Attack damage · Attack speed · Critical strike chance · Critical strike damage · Armor penetration · Magic penetration · Life steal · Omnivamp · Physical vamp · True damage 

Defensive  Heal and shield power · Health · Health regeneration · Armor · Magic resistance · Tenacity · Slow resist 
Utility  Ability haste · Energy · Energy regeneration · Mana · Mana regeneration 
Other  Experience · Gold generation · Movement speed · Range 