FAQ
Who can Diamond 3 duo with?
In Competitive, Diamond 3 can duo with a player from Platinum 3 – Ascendant 3.
Can Diamond 3 queue as a trio?
In a trio, both other players must be within Platinum 3 – Ascendant 3, and the gap between the party's lowest and highest player must also fit the rule.
Can Diamond 3 play in a 5-stack?
A 5-stack has no rank gap limit, so you can queue with anyone. If everyone is within Platinum 3 – Ascendant 3, there's no RR reduction; otherwise there is. A member outside the normal range means a 25% RR reduction. 5-stacks with an Immortal get a 25% RR reduction. 5-stacks with a Radiant get a 75% RR reduction.
These ranges are worked out from Riot's Competitive party rules with the same code PlusOne uses to check lobbies. Other modes don't check the rank gap. For the full picture, see Valorant party rank rules.