Party

Players can form parties to play matchmaking games with each other on the same team. Unlike a Guild or a Team, parties are not formalized and have no name or logo. Parties can hold up to five players and one coach.

Inviting
The party leader can invite players to the party by left-clicking on their name and selecting Invite to Party. They will receive a notification, prompting them to accept the invitation or decline it. If their Dota 2 client is not running, they will receive a desktop notification through Steam. You can invite players to your party through the friends list, match summary screen, or a chat channel. Players who are not the party leader can "suggest" an invite to the party in the same way. A player can open up their party to a specific guild, meaning that any player in that guild can join the party without a direct invite.

Teams
A team of five players can queue together in ranked matchmaking to have a persistent team identity and MMR. Players queuing as a team will only be matched up with other regular or team parties with five players.

Matchmaking
Ranked and unranked matchmaking keep track of MMR separately for playing solo and playing in a party of two or more. The matchmaking algorithm treats players in parties as having slightly higher MMR due to party coordination. Parties with five players are eligible to be matched against other parties of five that are queuing as a team.

Limitations

 * If any player in the party is in Low Priority, all players will be considered Low Priority.
 * If any player in the party has not unlocked a certain Game Mode, the party will not be able to queue for that Game Mode.
 * All players in the party must be eligible for ranked matchmaking to queue for it.
 * Parties that have members whose MMRs are 2000 or more apart are unable to queue for ranked matches.
 * Parties of four players are unable to queue for ranked matchmaking.