Game Mechanics

General Movement and Facing Rules

• At the cost of one action point, a unit may move forward into an unoccupied square in its front three squares.
• A unit can never move into a square that is occupied by a wall, another unit, a closed door, or flames. A model can not move through another model even if they have enough action points to end in a legal square on the other side.
• Diagonal movement forward or backward is allowed although a model may not "cut a corner" unless that corner is an allied unit (Diagram 1). If both orthoganal spaces to the diagonal are occupied by allied units, the diagonal cannot be made (Diagram 2).
• A unit keeps its same facing while moving. Many Tyranid units may turn for no AP cost after a move, although this is a separate action from the movement.
• All units may only face one of the four primary directions. They may not turn to face a diagonal for LoS/Firing Arc purposes.
• Backward movement that does not change a unit's facing is allowed and typically costs 2 AP. Blips do not face any direction.
• Strafing (moving to a side square without changing facing) is not allowed for most Marine units. The Terminator armor's leg articulators don't allow for much lateral movement.
• "Move and Shoot" actions are, for game purposes, Move then Shoot. The LoS and firing arc are traced from the square after movement is made.



Ranged Combat

Targeting is the ability to

• See a target (aka Line of Sight or LoS) and...
• the Firing Arc is the ability to bring a weapon to bear on a target.
If both these conditions are met, he can fire a carried and loaded weapon at that target. Sometimes, a unit may see an enemy in his LoS but will be not have the enemy in his firing arc. Some reasons for this could be...
• The enemy is too far left or right of the weapon's arc.
• The enemy is past the maximum range of the weapon.
• The enemy is behind transparent material.
Some weapons, like Flamers, require the targeting of a square, simply treat this as if a unit were in that square for targeting purposes.

LoS extends from the back of a unit's facing for 180° (see Diagram 3). If a model, wall, corner or flamed square is between the unit and the target, then LoS is blocked. Flames are a special case for LoS. A unit can see into the first square of flames (if a unit inside the flames survived) but not anything behind a square of flames.

Firing arc extends from the back of a unit's facing for 90° (see Diagram 4). Firing arc also extends for a certain number of squares in front of the unit based on the weapon being fired, i.e. the weapon's range. For range purposes, diagonals count as 1 square. This 90° arc up to a weapon's range is area that a ranged weapon can be used.

If a unit meets the criteria to shoot at a target, they roll a number of dice specific to their weapon. The highest die is the result. Modifiers are then applied if applicable. If the roll is high enough, the target is destroyed. After this ranged check, the dice are against checked for jams or explosions. So you could have a ranged attack where an Assault Cannon rolls 6, 6, 6, killing its target, then the explosion effect occurs, destroying the shooter.

Melee targeting if different. Close combat attacks can only be initiated against units directly in front of the attacker. Diagonals do not count here. Despite who initiates the melee attack, both combatants roll and compare a number of dice based on their melee ability/weapon. When rolling multiple dice, only the highest number is used, not a sum of dice. Many factors can modify these results, such as weapon bonuses, parries, or blocks. The unit who has the highest end result is the winner. If the winner is facing the opposing combatant, the combatant is destroyed. If the winner (or in a tie) is not facing the other unit, they may turn to face their attacker unit for no AP cost (even making a 180° turn), at the controlling player's discretion. If both combatants tie, then no unit is destroyed and that round's melee is over. An attacker may, of course, initiate another attack with another action point.

(Diagram 3) (Diagram 4)

A Space Marine player can react to actions within its LoS by using command points during the Bug Phase. If no action occurs within a unit's LoS, then no action can be taken. An action occuring within LoS does not necessarily mean a unit can fire. Only if the action is also within its firing arc can ranged attacks be made.