Added VULNERABLE_FROM_BACK bonus

client/battle/BattleStacksController.cpp

@@ -442,7 +442,9 @@ void BattleStacksController::stacksAreAttacked(std::vector<StackAttackedInfo> at
 
 		// FIXME: this check is better, however not usable since stacksAreAttacked is called after net pack is applied - petrification is already removed
 		// if (needsReverse && !attackedInfo.defender->isFrozen())
-		if (needsReverse && stackAnimation[attackedInfo.defender->unitId()]->getType() != ECreatureAnimType::FROZEN)
+		if (needsReverse &&
+		   stackAnimation[attackedInfo.defender->unitId()]->getType() != ECreatureAnimType::FROZEN &&
+		   !attackedInfo.defender->hasBonusOfType(BonusType::VULNERABLE_FROM_BACK))
 		{
 			owner.addToAnimationStage(EAnimationEvents::MOVEMENT, [this, attackedInfo]()
 			{

docs/modders/Bonus/Bonus_Types.md

@@ -413,6 +413,12 @@ Increases starting amount of shots that unit has in battle
 
 ## Static abilities and immunities
 
+### LIVING
+
+Affected unit is considered to be alive. Automatically granted to any unit that is not UNDEAD, NON_LIVING, MECHANICAL, GARGOYLE, or SIEGE_WEAPON.
+
+Living units can be affected by TRANSMUTATION, LIFE_DRAIN, and SOUL_STEAL bonuses
+
 ### NON_LIVING
 
 Affected unit is considered to not be alive and not affected by morale and certain spells
@@ -495,6 +501,12 @@ Affected unit will deal more damage based on movement distance (Champions)
 
 - val: additional damage per passed tile, percentage
 
+### VULNERABLE_FROM_BACK
+
+Affected unit will receive more damage when attacked from behind. Attacked unit will not turn around to face the attacker
+
+- val: additional damage for attacks from behind, percentage (0-100)
+
 ### HATE
 
 Affected unit will deal more damage when attacking specific creature

lib/battle/DamageCalculator.cpp

@@ -275,6 +275,15 @@ double DamageCalculator::getAttackJoustingFactor() const
 	return 0.0;
 }
 
+double DamageCalculator::getAttackFromBackFactor() const
+{
+	int value = info.defender->valOfBonuses(BonusType::VULNERABLE_FROM_BACK);
+
+	if (value != 0 && callback.isToReverse(info.attacker, info.defender, info.attackerPos, info.defenderPos))
+		return value / 100.0;
+	return 0;
+}
+
 double DamageCalculator::getAttackHateFactor() const
 {
 	//assume that unit have only few HATE features and cache them all
@@ -462,6 +471,7 @@ std::vector<double> DamageCalculator::getAttackFactors() const
 		getAttackBlessFactor(),
 		getAttackLuckFactor(),
 		getAttackJoustingFactor(),
+		getAttackFromBackFactor(),
 		getAttackDeathBlowFactor(),
 		getAttackDoubleDamageFactor(),
 		getAttackHateFactor(),

lib/battle/DamageCalculator.h

@@ -52,6 +52,7 @@ class DLL_LINKAGE DamageCalculator
 	double getAttackDoubleDamageFactor() const;
 	double getAttackHateFactor() const;
 	double getAttackRevengeFactor() const;
+	double getAttackFromBackFactor() const;
 
 	double getDefenseSkillFactor() const;
 	double getDefenseArmorerFactor() const;

lib/bonuses/BonusEnum.h

@@ -189,6 +189,7 @@ class JsonNode;
 	BONUS_NAME(MULTIHEX_ENEMY_ATTACK) /*eg. dragons*/	\
 	BONUS_NAME(MULTIHEX_ANIMATION) /*eg. dragons*/	\
 	BONUS_NAME(STACK_EXPERIENCE_GAIN_PERCENT) /*modifies all stack experience gains*/\
+	BONUS_NAME(VULNERABLE_FROM_BACK) /*bonus damage for attacks from behind*/\
 	/* end of list */