While remaining unaware of how the opposing player has arranged his or her army, the objective of the game is to be the first to seize the enemy's flag. Any movable piece can perform this task, but mobile characters are at the mercy of enemy characters that have superior ranks. Because the game is played blindly, a level of risk is involved with each move. When a challenge is made, the piece with the lowest rank is removed. If two pieces of identical rank meet in challenge, they are both removed. With the exception of the Scout (who can travel as far as possible in a straight line across any available spaces), all pieces may only move one space vertically or horizontally per turn. However, this rule does not apply to bomb or flag pieces, which must remain on their initial space for the entirety of the game. All mobile pieces are susceptible to bombs with the exception of the Miner character, who can "diffuse" the bomb and remove it from the board. The Scout character (which is the most numerous piece in the army) is relatively un-powerful on its own, but is the only movable piece in the game that can trump the most powerful character - a Marshall. There are many disputable strategies that exist among serious Stratego players, including certain bomb and flag placements, deceptive gameplay and general logistics behind moves. There have been multiple world championship competitions involving the game, with online tournaments becoming prominent in the late 2000's. Many classic and special edition versions of the game are currently available in both physical and digital formats, varying in price, artwork and layout and occasionally featuring smaller armies and board sizes.