No World of Warcraft knowledge needed. Terms in bold are the ones the rest of the wiki uses; the glossary has them all.
The game#
World of Warcraft is an online role-playing game from 2004 that is still played today. Each player controls one character of a class (Rogue, Mage, Priest and seven others), specialised into a spec such as a healer or a damage dealer. A character has dozens of abilities: attacks, heals, shields, escapes, and ways to stop an opponent from acting.
This project uses the game as it was in its 2010 version, Wrath of the Lich King, with the rules from its final competitive season. See which version of the game.
An arena match#
Arena is the game's competitive mode: a small team deathmatch.
- Two or three players a side (2v2 or 3v3). The comp (team composition) is the mix of classes on a team.
- A small map with pillars and walls. Most abilities need line of sight, so hiding behind a pillar is a defence.
- Everyone starts equal. Here, every character has the same top gear and every ability from the start. Nothing is bought or earned between matches.
- A few minutes a match. The team that eliminates the other wins. Healing is slightly weaker in arenas than elsewhere, which keeps matches from stalling.
- Ratings. Wins and losses move a team's rating up or down, like chess ratings.
What players actually do#
A match is a stream of small decisions made under time pressure:
- Cooldowns. Strong abilities can only be used every so often: once every two minutes, say. Knowing which of your own and the enemy's are ready is half the game. The enemy's cooldowns are never shown; players track them from what they have seen used.
- Crowd control. Stuns, fears and sheep-transformations stop a player acting for a few seconds. Repeating the same kind on one target works less and less (diminishing returns). A trinket breaks one on a long cooldown, so baiting it out matters.
- Casting and interrupting. Some spells take a second or two to cast, and an opponent can interrupt them. Good players start a cast and cancel it to bait the interrupt (a fake cast).
- Stealth. Rogues can be invisible until they strike, so their opening is a surprise.
- Positioning. Stay in sight of your healer but out of sight of their damage dealers; pull an attacker around a pillar; chase a fleeing target.
- Teamwork. Burst one target together, peel an attacker off your healer, and call out what you see, since teammates don't share a screen.
As a problem for AI#
Computers already beat the best humans at chess, Go, StarCraft II and Dota 2. Arena has a mix of what made those hard:
- Hidden information. Invisible units, unseen cooldowns and positions behind walls.
- Real time. Decisions every fraction of a second, with no turns.
- Long consequences. A crowd-control chain set up now pays off, or fails, ten seconds later.
- Teams. Two or three players who can only coordinate through what each sees and says.
This project adds one more constraint: the AI may only see what a player's screen shows and react as fast as a person can. It can't read exact positions, see through walls or react in a millisecond, so any edge it finds has to come from better decisions. See human parity.
Where to go next#
- The 264 meta: the gear everyone plays in.
- Comps: the teams the project starts with.
- Getting the game right: how the project checks that its copy of the game plays like the real thing.