Valve has teamed up with Richard Garfield, the creator of Magic: The Gathering to design their “trading” card game Artifact. Garfield approached Valve in 2014 wanting to create a digital card game that simultaneously paired the strengths of being digital with the freedom of play of a paper game. Being digital means the game can be larger in scale and complexity than a paper card game where physical tokens and calculations must be laboriously managed by hand. Digitally, calculations can be tracked and displayed by the computer, random numbers can be effortlessly generated, and unlimited numbers of units can be placed on the board, among many other advantages. Artifact will also replicate the metaplay freedom of paper games by allowing players to buy or sell individual cards or whole decks, lend their decks to friends to play with, and customize a huge number of parameters to tailor their own tournaments, matches, and drafts.
When work began on Artifact, it had no relation to the Dota universe. Valve has said that, at the outset, if none of their existing IPs was suitable for creating the kind of card game they wanted to make, then they would have created a new IP for it. However, Valve quickly found that Dota's wealth of mechanics, heroes, abilities, items, and lore was an ideal sandbox from which to draw. For instance, Garfield already had the initial idea of there being three fields of play in the game as a way to approximate the experience of playing a best-of-3 in a single game--it was felicitous that Dota happens to be structured into three lanes, making it a perfect analog. Dota's massive, open-ended, and flexible design space also allowed Valve to easily expand beyond what already existed in the Dota universe to accommodate all sorts of new ideas for Artifact, so Dota served as a rich starting point, not a set of constraints.
Valve will be using the Steam Marketplace to allow people to buy and sell cards. Gabe Newell has said he expects most cards to go for pennies, with supply and demand dictating the market prices. Newell has commented that Valve doesn't want Artifact to be pay-to-win, calling it "pernicious". To this end, card power and card rarity do not align, which sharply contrasts with Hearthstone and MtG.
Artifact is being made with the Source 2 engine. It will be released November 28th on Steam and later it will come to mobile platforms--the first Valve game and Source 2 game to do so.
The game board is partitioned into three lanes. Play progresses in sequential phases from one lane to the next. Each player in each lane has a Tower. Towers start with 40 HP and 3 Mana; each round, every Tower's Mana pool automatically increases by 1 and replenishes. Once a Tower is destroyed, an Ancient, with 80 health, is exposed. The only way to win the game is to either destroy two enemy Towers or the enemy Ancient.
Each deck consists of at least 40 cards, including 5 heroes and 15 signature cards (3 per hero, which are automatically included with the hero). There is no maximum deck size. There are 44 heroes to choose from in the game. In future expansions, there will be a mix of additional heroes adapted from Dota 2 and all-new ones.
Like in MtG, all cards except items have colors to denote their school/play-style. The colors are blue, green, red and black. Each hero also has one of the same four colors, and a card can only be played if you have a hero of matching color active in the current lane. If you have no heroes in a lane, you cannot play any cards in that lane!
Three heroes are deployed at the beginning of a match, one in each of the three lanes. You pick which of your five heroes will be in your starting three, but it is random which lane gets which hero. You other two heroes become available for you to deploy into lanes of your choice starting in the second turn. When a hero dies, it is removed from the board for two turns before it can be redeployed.
At the start of each round, two melee creeps spawn for each player randomly across the three lanes. At the start of play in each lane, all heroes and creeps in the lane randomly choose combat targets in front of them. Each unit has a 50% chance to attack directly in front of itself and a 25% chance to attack to either of its forward diagonals. There are many cards capable of altering friendly and/or enemy combat targets, so it is up to players' strategic decision making when and where to play such cards.
Unlike Hearthstone or MtG, players alternate playing cards via the Initiative system. Playing a card passes Initiative to the other player, allowing them to play the next card. Whichever player chooses to pass their turn first without playing a card will retain Initiative at the start of play in the next lane. This creates a key strategic choice throughout the game of deciding between playing a card in the current lane or abstaining in order to play the first card in the next lane.
As in Dota, but unlike in other card games, gold is accrued by killing enemy heroes and creeps. During the Shopping Phase at the end of each round, Gold can be spent on equipment and consumable items. Heroes wear equipment in their weapon, armor, or accessory slots. Equipment remains on a hero even after it dies and respawns.
Unlike Hearthstone, there is no limit to how many units can be on the board at one time. There is also no limit to the number of cards a player can have in hand. Running out of cards in one's deck carries no penalties--it just means that player won't be able to draw anymore cards for the rest of the game.