Glossary

The terms used in the action rule tables.

Distances

Hex Distance: Distance counted straight across the hexes. It ignores both terrain and units.
Move Distance: The shortest distance in terrain cost to a hex from which the target can be attacked, going around what cannot be entered — impassable terrain and hexes holding units. If no such hex exists the distance cannot be measured, which is the case for a flier seen by a unit with no Atk vs Air.
Terrain Distance: Move Distance with units removed from consideration — measured over terrain alone. Whatever is in the way will move eventually, so the road beyond it still counts.
Detour Distance: Move Distance with enemy zones of control avoided as well. The target's own zone is not avoided, since avoiding it would make it impossible to reach the target at all.
Sight Distance: Distance measured by adding up a sight cost per terrain: open ground is 1, woods and low obstacles are 2, high obstacles are 3, and walls do not let it through. It is not straight distance — it stretches through woods, and a wall casts a blind spot behind it. A fence is posts and rails, so it does not fill the hex and does not block sight. Screening with your front line can keep the units behind it unnoticed.
Not Measurable: When no route to the target exists once the excluded hexes are taken out. What a unit does in that case is decided by its own action rules.

Movement

Move Range: The set of hexes the unit can end its turn on. Zones of control cut it short, though the stopping hex itself is included. Hexes with a friendly transport it can board are in the set too.
Advance: Moving to whichever hex in Move Range shortens the distance to the target most. It comes in four flavors by which distance it uses: full advance uses Move Distance, flanking uses Detour Distance, projected advance uses Terrain Distance, and straight approach uses Hex Distance. If nothing shortens it, the unit stays put.
Max Standoff: Moving to the hex in Move Range from which the target can still be hit and which is furthest from it. It never goes beyond its own maximum range, since that would mean it cannot shoot. Enemy Move is not taken into account, so it can still be closed down next turn.
Threat Range: The set of hexes where some enemy on the board could attack the unit after moving its full allowance. Each enemy's reach is measured and its range added on top, then all of them are combined. It is the sum over every enemy, so one fast unit widens it a great deal.
Spacing: Moving to the hex in Move Range that lies outside the Threat Range and is closest to the target in Move Distance. Too near and it backs off, too far and it closes — both fall out of the same rule. If there is nowhere outside the Threat Range, it does not move.

Choosing Targets

No Counter: When shooting from that hex draws no return blow. It holds if the distance is 2 or more, or the target cannot shoot distance 1, or the target has no way to attack the unit at all. It follows purely from ranges, distance and unit types, so you can read it off the board.
Wounded: Among the enemies the unit can attack, the one that has lost the largest share of its strength — ties going to the one nearest in Move Distance. When nobody is hurt, the closest enemy is the wounded one. Exactly one is picked, from the whole board.
Prey: Among the enemies the unit can attack, those whose defense falls within ten of the softest one. It is a set rather than a single unit, and strength is not considered — it depends on stats alone, so you can tell who is being hunted. The threshold is worked out from every enemy on the board.
Air Target: A flying enemy that can be attacked by a unit good against air — one whose Atk vs Air is at least its Atk vs Ground. Units that are not good against air have no air targets, which keeps something like 70 ground against 10 air from being sent skyward.
Blocker: An enemy standing in the way. It is judged by imagining every shootable enemy removed at once and asking whether the Move Distance shortens or a previously impossible detour becomes possible. They are not tested one at a time, because a corridor held by two units does not open when only one is taken away.
Lethal Target: An enemy that the attack would reduce to zero strength. It is counted from shooting where the unit currently stands, so Encircled, Support and Terrain are already in the figure — change your formation and the answer changes. Combat is simultaneous, so the kill still draws a counterattack.
Damage: How many soldiers the attack would take off the target. Maximum strength is the same for every unit so it is counted outright rather than as a share.
Can Encircle: That the allies already adjacent to the target, plus those yet to act that could reach a neighboring hex this turn, add up to the number needed for Encircled. The acting unit counts itself. Anything already surrounded always qualifies.
Attrition: The share of strength lost. It is read as a proportion rather than a remainder, so units with different maximums can be compared.
Hitching a Ride: Boarding a transport to be carried to the destination. The turns it would take on foot are compared with the turns it would take aboard, and the unit boards only when the ride is faster; a tie means walking. When the transport can cross terrain the unit cannot, walking is not measurable at all and the ride always wins.

Squad Parameters

Sight: The sight distance used for activation, set per squad by the stage. Two squads on the same trait can carry different values.
Retreat Threshold: A share of attrition. Past it the unit turns to withdrawing: under Flee the destination switches from an enemy base to one of its own, and under Withdraw it pulls back to a base.
Stack Condition: What keeps the enemy from piling skills onto one target forever. For buffs and debuffs it asks whether fewer than the limit are already in place; for cleansing it asks the opposite — whether at least the threshold number of debuffs are stuck on. With no limit set, buffs and debuffs always qualify.