Riot has updated the description of ranked matches in League of Legends.
Ranked games are one of the more important parts of League of Legends because of the competitive aspect that many players want to experience online. In LoL, it is a solo/duo queue where you can play alone or with a friend, but not everyone can play with everyone.
Riot shared a special schedule and a description where you can find out who can play with whom, and it all depends on which divisions the players are in.
Who can play with who on rankeds?
Since Solo/Duo is more focused on individual performance, there are limitations on who you can queue with.
IRON—DIAMOND
Most players can queue with friends within one tier of their rank, but these restrictions start a little loose at lower ranks and get tighter the higher you go. For example, Iron players can queue with players up to two tiers their senior! But ascend to Diamond, and your buddy must be within two divisions to join your party.
MASTER+
Reaching Master tier is a tremendous accomplishment, but it’s also the start of a whole new journey where only the best can ascend. That’s why players in Master or higher must queue alone. There’s only room for one at the top!