Summoner icon

A summoner icon is an avatar picture that represents you in your friends' friend list, in chat rooms, in custom games and in arranged teams. There are currently 29 starter icons (excluding the Pulsefire Ezreal one), but more will eventually be able to be earned through different achievements.

Standard icons
There are currently 29 standard summoner icons.

Unlockable icons
Currently there is only 1 summoner icon that can be unlocked. This icon can be obtained when purchasing the Pulsefire Ezreal bundle in the shop.

Limited availability icons
Currently there are only icons that could be unlocked during events or the end of seasons. The varying events are listed below.

Season 1 Reward Icons
These icons were handed out at the end of season 2, together with the season 2 reward icons. They are based on a summoners (solo queue?) ranked rating at the end of season 1.

Season 2 Reward Icons
Season 2 reward icons were distributed along with season 1 reward icons at the end of season 2. They were based on the highest rating a summoner earned during 2 month window near the end of season 2. This window ranged from September 12, 2012 until November 6, 2012.

The icons were determined based on both the rating (tier) achieved and the queue in which the rating was achieved. Having a higher tier rating would automatically unlock the lower tier icons as well. The required ratings can be found here: http://competitive.na.leagueoflegends.com/season-two-rating-tiers.

There are 5 different tiers that could be achieved: bronze, silver, gold, platinum and diamond. Each tier is represented by the colour of the chalice on the icon.

Summoners could get icons for 3vs3 team queue, solo 5vs5 queue and 5vs5 team queue. Each queue is represented by a gem on a certain part of the chalices. Gems around the top of the chalice represent 3vs3 queue. A gem in the middle represents solo queue and gems around the base represent 5vs5 queue. When a summoner has the requirements for all the queues in a certain tier, he or she would receive a bonus icon, that would combine all three gem ornaments into one icon.

Season 2 Championship
During the season 2 championship world finals, Riot showed a code on the stream to unlock a summoner icon inspired by the Championship Riven skin. Summoners had 24 hours to redeem this code.

The icon consist of a black-blue sword (Rivens sword) on a blue background. On front of it you could see the Roman number II, representing season 2.

Harrowing Icons (Halloween 2012)
These five Sinister Summoner Icons were offered with the purchase of RP during the 2012 Harrowing event. The five Summoner Icons were placed into tiers of bought RP and determined which icons you received. If you bought RP from a high tier you also received the icons form the tiers below it (e.i. if you bought RP enough for the tier 3 icon, you would also receive the icons for tiers 1 and 2).

Freljord Icons
These three summoner icons were made available to unlock during the Freljord patch, v3.6. Each icon symbolizes a tribe of the three Freljord Princesses:, , and. Even though there are three, a summoner is only able to unlock one of them to declare their allegiance to a tribe. To unlock the the one you want, a summoner must first set their profile icon to the temporary icon of the one they want, which can be selected immediately. These temporary icons look just like the actually ones, except they a timer symbol at the bottom left corner of the icon. Then you must win ten games against real players (any game mode will count) without changing the icon. Victories in bot games, however, will not count towards unlocking these tribal icons, which are expected to be available to be unlocked until May 14th. For more information please check out Riot's official Battle for the Freljord announcement.