The game has been evolving since its release. New game modes, updated maps and champions, Riot Games doesn't leave any downtime and is constantly looking to delight players with new features. Unfortunately, sometimes you have to make room and make sacrifices: Dominion mode, the Tribunal or the Magma Chamber — they have all joined the Riot Games cemetery.
Dominion
Dominion mode was introduced on September 23, 2011; previously, it had been shown at the Gamescom and Pax in August 2011. It was a 5v5 map called the Crystal Breach. Unlike the Summoner's Rift, where the main gameplay is to destroy the opponent's base, Dominion mode was played on point capture. When a team captured one, the opponent's nexus lost health points.
In the Crystal Breach, there were various buffs, such as those used to increase the speed of movement, healing buffs, and the two Great Relics, which gave the corresponding team damage and armor bonuses. The Dominion mode had its own Summoner's spells: Fortify and Teleport which were replaced at patch 1.00.129 by Garrison and Promote (which later became the command banner). The year it disappears, the Dominion mode will have a last farewell round with the temporary mode: Ascension, celebrating the rework of Xerath, Sivir, and the arrival of Azir. A player could become Ascended, which made him grow, and gave him incredible damage and resistance bonuses.
Due to a lack of popularity, the game mode was removed from the client on February 22, 2016.
The Tribunal
The Tribunal is a system that was introduced in May 2011 by Riot Games. Players could go to the League of Legends website, and judge their peers by reading the chat extracts, where they had been caught in the act of toxicity. You had to be at least at level 20 to be able to participate, without having been banned by Riot Games beforehand.
Several members of the Tribunal were judging the same player, based on violations of the Summoner's rules. We could even access his score as a judge! It was withdrawn in 2014 (and we miss it).
The forgotten
The Magma Chamber had been announced in 2016, based on the style of the Summoner's Rift, except it was a 2v2 map. Unfortunately, the project was canceled that same year. To win the game, you had to kill 100 henchmen, destroy the first turret, or take the First Blood.
Finally, we will have to say goodbye to the Twisted Treeline at the end of season 9. There is no more 3v3, and Riot makes room to leave Teamfight Tactics permanent and free a place for rotating game modes.