Pursuit happens when a stack retreats or rout from a battle. Pursuit is the act of taking hits when doing so. The parameters influencing pursuit losses are:
Screener attribute Elements with the *Screener* attribute will reduce damages by a maximum of 50%.
Stacks targeting the retreating stack are all factored. For each enemy element, we calculate what will be the damages they do to the retreating stack, as follow: If range > 0, then it is proportional to these stats OffFire, Damage Done, and inversely proportional to terrain cost(1). If range was assault, then it is proportional to Assault Damages and inversely proportional terrain cost(1).
(1)Fast elements will do much more damages than slow elements when pursuing.
If the element is a disrupter (Disrupter attribute), then the damages are increased by 50% for this element.
If the stack is routed (compared to in retreat) then the damages are increased by x2.5
As said above, a damage reduction will be impacted if some retreating elements are screeners.
All the pursuing elements damages are then added up then multiplied by 8% (a legacy 'control' variable which is not exported, but you can alter the damages taken with others variables, see below).
The damage sum is then modified by the number of rounds since combat is started (The reasoning is: the longer the battle raged, the more difficult it will be to pull out). So the damage sum is 50% + 10% per round of battle. These variables are exported and allow you to change easily the overall losses incurred from pursuit:
cbtRetreatBaseCoeff = 50
cbtRetreatCoeffChangeRnd = 10
Usually found in Combat&Retreat.opt, or in GameLogic.opt for VGN.
A set of 5 variables also alter this damage sum, depending of the size of the retreating stack:
cbtRetreatCoeffBaseSize = 75 // 75 SU don't change damages because of size of retreater
cbtRetreatMoreSizeChunk = 1 // each 1 SU above BaseSize (75) leads to +1 damage %
cbtRetreatLessSizeChunk = 1 // each 1 SU under BaseSize (75) leads to -1 damage % (so 1 SU retreating = -74% damages)
cbtRetreatMaxSizeMod = 200 // Can't take more than 200% of damages because of big size
cbtRetreatMinSizeMod = 25 // Can't take less than 25% of damages because of small size
10 Cossacks are pursuing 5 infantry regiments and 2 cavalry squadrons. The terrain is marsh (4 days of travel of Cossacks), round number 2, the range was assault.
Damage done by pursuit will be:
Cossacks Num x (DaysPerTurn-DayCost) x Assault Dmg augmented by 50% (all cossacks are disrupter) (10 x (15-4) x 3) x 150% = 495
Legacy control variable 8% Damages down to 495 x 8% = 39.6
Some retreating elements are screeners (each screener has a weight of 2) Damage reduced by 2x2/7 = 57%, but the maximum reduction allowed is 50%, so 50% Damages down to 19.8
This is 2nd round, so 70% of losses only, damages down to 13.86
Size of the retreating stack is 7, this is 68 elements below 'no modification' and each element under the 'no modification' reduces by 1% damages, so we get a -68% from small size, damages down to 4.43
Rounded to 4 hits.
If the retreat was a rout, this would be 10 hits (x2.5).