Summoner spell

Summoner Spells are abilities that a summoner can use to assist their champion on the Fields of Justice. They are chosen in Champion Select before the start of the game. Each player is allowed two summoner spells chosen from a list. Summoner spells can be used in game to aid a player’s champion in various ways as each spell has a unique effect. Some summoner spells increase in effectiveness relative to your champion's level, but many provide the same effect at champion level 1 as they do at champion level 18. They do not have any cost other than their cooldown.

Unlocking Summoner Spells
The number of spells that are available to a player are determined by their summoner level. At summoner level one, a player begins with six spells to choose from. Then as a summoner reaches new levels, he or she will unlock new spells up to level twelve. The table below shows what summoner level unlocks which spell(s):

Unavailable Spells
These spells either became obsolete due to game mechanics changes or were removed because they were too strong.

Summoner Spells and Champion Level
During combat the spells (,, , and ) gain power with champion level. The other spells have the same power throughout the entire battle. While in combat the spells are bound by the same rules as the champion skills, however, and  are the only summoner spells that cannot be used while silenced or stunned.

Reducing Summoner Spell Cooldowns
Summoner spells cooldown reduction stacks multiplicatively. Note that is the only spell with a flat cooldown reduction bonus, which is calculated last. In season 3, there are a few ways to reduce the cooldown of summoner spells which include:
 * The mastery, which is the only way to reduce the cooldown of all Summoner spells. It does so by 4/7/10%., depending on how many points you put into the mastery.
 * The enchantment for boots which reduces the cooldown of,  and  by 25%.
 * The item which reduces the cooldowns of,  and  by 25 %.
 * The item  which reduces the cooldown of by 20%.

Summoner Spells and Game Modes
Currently there are three game modes in League of Legends: Classic, Dominion and ARAM.

Due to the different characteristics of each game mode, some summoner spells are excluded from a mode while other spells are available specifically for a particular mode. And there are also common summoner spells which are available in all modes. The current set of summoner spells available in Classic mode are the same for Dominion with the exceptions of and, which replace one another. The following table shows what modes are available for each spell: