This game takes place during The Valkyrie Incident, a time of war and dissension between the five Valkyrie Clans. The game is played over a series of Engagements (or rounds), split betwen a Draft Phase (where each player can Recruit cards for his deck) and a Way Phase (where players play the cards from their decks to win conflicts). With its focus on player interaction, multiple ways to use each card, and a variety of ways to score points, The Valkyrie Incident is unlike any other deck building game. The game is fast, chock full of choices and player interaction.

There are six different card types: Valkyrie, Cogdrives, Actions, Assaults, Locations, and Emblems. Each of the first four card types are included in the main deck. Each card has a Clan Emblem (this is the clan it belongs to), a Recruit Cost (this is in the gray), a Strength Value (this is in red), and a special ability which can be used during either the player’s Recruit Turn, or during his Conflict Turn.

At the beginning of each game, each player selects an Emblem. Every card recruited by the player is worth 1 point. However, cards of the clan of the player's selected Emblem are worth an additional 1 point. Emblem also grant the player a special once per Conflict ability and a chance to score bonus Conflict cards during the Recruit Turn. Each Engagement, the player who started the War chooses which location the Conflict will take place in. Each Location has an overall effect for the Conflict.