Matchmaking is the process through which the system groups players into opposing teams for public games. With the exception of bot games, matchmaking is mostly determined by matchmaking ratings (MMR).
Valve has stated that matchmaking tries to fulfil several criteria:
- The teams are balanced. (Each team has a 50% chance to win.)
- The discrepancy in skill between the most and least skilled player in the match is minimized.
- The highest skill Radiant player should be close to the same skill as the highest skill Dire player.
- The discrepancy between experience (measured by the number of games played) between the least experienced player and the most experienced player is minimized.
- Each team contains about the same number of parties.
- For example, the matchmaker tries to avoid matching a party of 5 against 5 individual players.
- Players' language preferences contains a common language.
- Wait times shouldn't be too long.
Unranked or casual games do not display matchmaking ratings and still doesn't track your MMR for solo and party queues.
- All PvP game modes are available for unranked matches.
- Ranked matchmaking allows players to earn a seasonal ranking, along with a badge that can be displayed next to the profile. Seasonal rankings are reset at the end of each season. See the main page for pictures of badges and division details.
- Only Ranked All Pick, Captains Mode, and Random Draft are available for ranked matches.
- Players can choose to be matched only against other solo queue players.
- Separate MMRs are maintained for Core and Support roles.
- Unlike casual matches, MMRs for all players in ranked matches are made visible at the endgame screen.
Requirements and restrictions
- Players must link a unique phone number to their Steam account in order to queues ranked matches.
- Phone numbers can be removed or changed, but there is a three month waiting period before the same phone number can be used again on any account.
- Players must be at least level 20.
- Parties with any player below the Profile Level requirement will not be able to queue for ranked matches.
- Players must play 10 trial games for the system to calibrate their MMR.
- Calibrated MMR cannot be higher than 3500. Players more skilled than that threshold must work upwards from this limit.
- Players in Low Priority cannot queue for ranked matches.
- Parties with any player in Low Priority will not be able to queue for ranked matches.
- Coaches are not permitted in ranked matches.
- Parties with members whose MMRs are 3000 or more apart are unable to queue for ranked matches.
- Any form of Abandonment will incur full penalties for the entire party.
- Any player who abandons will automatically receive a loss, regardless of the match's outcome.
This function matches you against another player in the Mid Lane. This match is over when one player dies twice, loses a tower, resigns or disconnects. Type gg in chat to resign.
This function matches you or your team against AI-controlled bots.
- Co-op bot matches are always played in All Pick mode.
- No MMR is tracked for bot matches.
Settings allow players to be matched only with others who have selected the same settings. Selecting more settings can significantly reduce wait time, as the system will be able to search for compatible players from a larger population pool.
Game Modes determines which modes you would like to queue for. Checking more game modes will increase matchmaking speed.
Current game modes for public matchmaking include:
- All Pick
- Captains Mode
- Single Draft
- Random Draft
- Least Played
- All Random
- Captains Draft
- Ability Draft
- All Random Deathmatch
Region determines which regional server you would like to play on. Checking more regions will increase matchmaking speed, but may cause latency issues if the server location is far away. You can select up to 3 regions. It is recommended that you only choose regions where the language you speak is the dominant language for that region, this is to avoid people reporting you from speaking another language (this does happen).
Current regions include:
- US West
- US East
- Europe West
- Europe East
- SE Asia
- South America
- South Africa
- China UC
- China UC 2
- China TC Shanghai
- China TC Zhejiang
- China TC Wuhan
The language window allows you to select up to 2 languages. You will be matched with other players who have selected the same languages. Checking more languages will increase matchmaking speed. If no languages are checked, you will be matched with the current language of your client.
All PvP matchmaking is based on an Matchmaking Rating (MMR) similar to the Elo system. Players of roughly equal skill will be placed in the same game.
Priority determines how quickly the player is matched with other players. There are 3 types of priority: high priority, base priority, and low priority. Players in low priority will not gain battle points from the match, will find games more slowly, and will only be put with other players in low priority. Low priority is a common punishment for abandonment. Base priority is granted to any player when they enter a matchmaking queue provided that they are not in low priority. High priority is granted when a player is returned to queue after a recently failed matchmaking attempt due to another player failing to connect to the game or declining the Ready Check.
Players may be banned from matchmaking for a period of time due to several offenses.
- Declining or failing to ready for a match.
- Abandoning too many matches.
- Poor in-game behavior.
- Too many reports from other players.
Behavior Score and Account Flags
Match quality is presumably determined by a combination of the player's behavior score and their account flags value. Players with a high behavior score get matched with other players with a high score and vice versa. The account flags supposedly determine in which matchmaking pool a player should be, independently of their mmr and behavior score. The current behavior score and account flags can be checked using the Console through the commands
dota_game_account_client_debug | grep behavior
dota_game_account_client_debug | grep flags
The behavior score shows as grades . Possible Grades are Normal (encompassing the scores formerly labeled as A+, A, B+, and B), C+, C, C-, D, and F. While Normal being the highest and F being the lowest. Valve has not disclosed how these scores are calculated, but abandons, reports and commends seem to play a role.
Account flags are represented as an integer value. Most players report having an account flag value of 0, 1 or 3. It is known that account flags with values 7 indicates that a 6-month ban is imminent on the account, but there is no known effect on matchmaking.
Shadowpool is a status placed on an account that is typically assigned to players who have abused of exploits in the past. Shadowpool status is not reported anywhere client-side.
Players in shadowpool will:
- Remain matched with other players in shadowpool or players with a very low behaviour score (independently of their own). Queue times are generally much longer in shadowpool.
- Be ineligible to appear on the leaderboards, and will thus not receive a rank if they have achieved the immortal medal.
The shadowpool status can either be permanent or temporary. However, this information can only potentially be revealed through a request to the Steam support.