Arimaa/Camel and Horse Attacks
Objectives and Risks
Camel and Horse Attacks are normally used as a counter-attack in response to an attack by the enemy Elephant on the opposite side of the board. Camel and Horse Attacks can also be used as part of a Double-Trap Attack.
Note: For simplicity, many examples below will assume that the Gold player is attacking the c6 trap. Naturally, the same theories can apply equally to attacks on all 4 traps.
Reasons to use a Camel and Horse Attack:
- to generate a counter-attack against an enemy trap that is not defended by an Elephant or Camel
- to take control of an enemy trap when the enemy elephant and camel are unable or unwilling to defend the trap (e.g. when the enemy camel has been taken hostage)
- to create a goal threat
- to distract the enemy Elephant
- to complete a double-trap attack
Risks involved in a Camel and Horse Attack:
- Either Horse or Camel can be taken hostage or trapped if the enemy Camel or Elephant approaches the trap.
- Home traps may become weakened.
Ideal Placement of Pieces
The ideal placement of pieces will depend greatly upon the board situation. If the Silver Elephant is protecting a Camel hostage at f3, it may be advantageous for Gold to launch a Camel and Horse Attack against c6. In that case, the Gold Camel should be kept safe so that the Silver Elephant cannot escape the hostage situation at f3 by trapping the Gold Camel at c6. Ideally, the Horse and Camel should be placed on b6 and c7 and additional attacker(s) are often called up to secure and defend the trap. A third or fourth attacker not only assists in controlling the enemy trap but will also create greater difficulties for the Silver Elephant if it crosses the board to disrupt the attack. An attacker should never occupy d6 unless the f6 trap can be secured by friendly pieces or all the stronger enemy pieces can be kept away from the d6 square.
If the Gold Elephant is already attacking the f6 trap then the Gold Camel is normally best placed on the b6 square with the Horse on d6. This places attacking Camel as far as possible from the defending Elephant while still holding the ideal b6/d6 attacking formation. However, if the Silver Elephant is blockaded, or otherwise unable to reach the d6 square, then it may be preferable to centralize the Camel at d6 due to its greater strength.
During a middlegame or endgame in which the Camel and Horse are being used to facilitate a Rabbit advance, the Gold Camel is normally placed on the c7 square. From this square, the Camel may still maintain a safe distance from the Silver Elephant while also threatening enemy pieces participating in back rank goal defense.
Defensive Systems and Counter-Attacks
The easiest way to defend against a Camel and Horse Attack is to move a Camel or Elephant toward the same trap with the intention of taking a hostage. This is not always possible because the attacking player will normally attempt to seize a weak trap which cannot be easily defended by either the Camel or Elephant.
Camel and Horse Attacks are often intended as a counter-attack to offset/distract an enemy Elephant attack on the opposite wing. In these cases, it is recommended that the attacker bring at least three, preferably four, attackers so that the Silver Elephant cannot easily return to the home trap and capture the Gold Camel. It is not difficult for a defending Elephant to hold two attackers hostage while threatening to trap a third - hence, four attackers are often recommended. It is uncommon for an opposing Elephant to commence an attack on the opposite wing in response to a Camel and Horse Attack.
If the Gold player is contesting the f6 trap (with an Elephant and Horse Attack, for example), a second attack against the c6 trap could be devastating for Silver. Therefore, it is necessary for silver to either counter-attack with the Camel to preempt or prevent a Gold Camel and Horse Attack or, at the very least, to secure the b6 and c7 squares with strong pieces.
Ideas for Setup
For simultaneous attacks against both enemy traps during the opening phase, see the next chapter.
Balanced forces are important during the game both to launch, and defend against, a Camel and Horse Attack. As such, most players will setup an Elephant and Horse on one half of the board and a Camel and Horse on the other. Setting up and maintaining the Camel on the home rank middle is a good strategy to protect against a Camel-drag but is not ideal if the Camel wishes to participate on either side of a Camel and Horse Attack.