Range

Range is a measurement used to determine how far an autoattack or ability can reach. Riot tends to describe that distance in a vague unit of measure called Units. It shares the scale of "units" with movement speed, so one point translates to one game distance unit traveled. Note that autoattack range is measured differently to ability range. Given a source unit's hitbox and a target unit's hitbox, range is calculated as follows: autoattack range from edge to edge; targeted skill range from center to center; skillshot range from edge to edge; and the range of self-centered area of effects are from the edge of the source (the larger champions don't benefit less from auras than smaller champions). The difference is approximately 100 (i.e. 550 autoattack range is roughly 650 casting range)

Each champion begins the game with a particular base autoattack range. This can vary from 125 to 200 for melee units and 400 to 650 for ranged units. The highest base autoattack range for champions is held by. At level 18, the highest autoattack range is 669 held by surpassing  at level 16 with 650 autoattack range. This is because of.

Attack Range Modifiers
The following abilities increase the champion's respective attack range, without affecting things such as, , , , , and.
 * increases his attack range to 325 from 150 for 12 seconds.
 * replaces his basic attack with Sand Soldiers 375 attack range attack that can be used if Azir is in 800 units range from soldier
 * increases her attack range by 650 for her next attack against targets affected by or.
 * increases his attack range by per stack. The maximum is +50 at rank 3 and 6 stacks.
 * increases his attack range to 200 from 175 for his next attack.
 * increases his attack range to 150 from 125 for his next attack.
 * increases his attack range to 425 after dashing, and causes him to blink to his target upon auto attack.
 * increases his attack range to 325 from 175 for the attack.
 * increases her attack range to 350 from 125 for the next attack.
 * increases her attack range to from 525.
 * increases his attack range to 200 from 150 for the attack.
 * increases his range to 175 from 125 upon evolving the ability after leveling his ultimate,.
 * increases his attack range to from 500 for 8 seconds.
 * increases her attack to 155 from 125 for the attack.
 * increases his attack range to 175 from 125 for the duration.
 * increases her attack range from 125 to 200 for the attack.
 * increases her attack range to 525 from 125 for the attack.
 * increases his attack range to 175 from 125 for the attack.
 * increases his range to 600 (725 with 6 trophies on ) from 125 while in brush and 0.5s after leaving brush, causing him to leap at his target.
 * increases her attack range to 200 from 125 for 15 seconds.
 * increases her attack range to 175 from 125 for her next attack only. Her attack range is increased to 150 for the area of effect portion of the spell.
 * increases her attack range to 175 from 125 for the duration.
 * increases her base attack range of 543 by 7 with each level (+ 126 at level 18).
 * increases his attack range to 850 from 550 for 7 seconds.
 * increases her attack range to 175 from 125 for the attack.
 * increases his attack range to 300 from 175 for the attack.
 * increases his attack range to 175 from 125 for the attack.
 * increases the attack range of the champion's next attack by 35%, capped at 150 bonus range.

Range Type Modifiers
The following abilities change a champion attack classification from "Ranged" to "Melee", or vice versa. This affects things such as, , , , , and.
 * decreases her attack range to 125 from 550 until she switches stances.
 * decreases his attack range to 150 from 400-485 until he switches stances.
 * increases his attack range to 500 from 125 until he switches stances.
 * increases her attack range to 525 from 125 for 10 seconds.
 * decreases her attack range to 125 from 525 until she switches stances.

Size Model Modifiers
Ranges calculated from the of a champion's hitbox will see an increase or decrease in reach based on the champion's current size. Note that a change in range due to the champion's size is only relative to the champion's center and is not an explicitly mentioned effect (i.e. the champion's attack range stat will not increase).

Innate
Thus far, is the only champion with the innate quality of constantly modifying his size.
 * His maximum size is increased by his maximum health.
 * His current size fluctuates based on his current health percentage.

Size Increase

 * (also grants explicitly increased attack range)
 * (also grants explicitly increased attack range)
 * (On himself)
 * (On himself)
 * (On himself)
 * (On himself)

Size Reduction

 * (On target)

Items
While the following items do not explicitly increase the champion's attack range, they do increase the champion's size - allowing them to reach targets further away from their current location:

Other

 * Crystal Scar's

Chart
List of ranged champions from highest to lowest autoattack range. List of Melee champions.

Targeted Abilities (Exceptions)
The following targeted abilities calculate their range like a basic attack (edge-to-edge):
 * and
 * This list may be incomplete.
 * and
 * This list may be incomplete.
 * This list may be incomplete.
 * This list may be incomplete.