diff --git a/common/ruletypes.h b/common/ruletypes.h
index 37bf96711..ce00b7e51 100644
--- a/common/ruletypes.h
+++ b/common/ruletypes.h
@@ -167,6 +167,7 @@ RULE_BOOL(Character, EnableCharacterEXPMods, false, "Enables character zone-base
 RULE_BOOL(Character, PVPEnableGuardFactionAssist, true, "Enables faction based assisting against the aggresor in pvp.")
 RULE_BOOL(Character, SkillUpFromItems, true, "Allow Skill ups from clickable items")
 RULE_BOOL(Character, EnableTestBuff, false, "Allow the use of /testbuff")
+RULE_BOOL(Character, FixHPCalculationOverflow, true, "Fix the HP overflow bug in HP calcs, this is a client bug, if fixed and clients overflow their hp wont match the server's hp but the difference serverside can be significant so it's left as an option.")
 RULE_CATEGORY_END()
 
 RULE_CATEGORY(Mercs)
diff --git a/zone/aa.cpp b/zone/aa.cpp
index 5acce37d6..0d5416c9f 100644
--- a/zone/aa.cpp
+++ b/zone/aa.cpp
@@ -966,7 +966,7 @@ void Client::SendPhantomStatsAlternateAdvancementRank() {
 	for (int i = 0; i < 7; ++i) {
 		outapp->WriteSInt32(SE_RaiseStatCap);
 		outapp->WriteSInt32(diff);
-		outapp->WriteSInt32(0);
+		outapp->WriteSInt32(i);
 		outapp->WriteSInt32(i + 1);
 	}
 
diff --git a/zone/bot.cpp b/zone/bot.cpp
index 531dba75f..1487f2045 100644
--- a/zone/bot.cpp
+++ b/zone/bot.cpp
@@ -25,6 +25,7 @@
 #include "lua_parser.h"
 #include "../common/string_util.h"
 #include "../common/say_link.h"
+#include "../common/data_verification.h"
 
 extern volatile bool is_zone_loaded;
 
@@ -7919,24 +7920,31 @@ uint32 Bot::GetClassHPFactor() {
 }
 
 int32 Bot::CalcMaxHP() {
-	int32 bot_hp = 0;
-	uint32 nd = 10000;
-	bot_hp += (GenerateBaseHitPoints() + itembonuses.HP);
-	nd += aabonuses.MaxHPChange;
-	bot_hp = ((float)bot_hp * (float)nd / (float)10000);
-	bot_hp += (spellbonuses.HP + aabonuses.HP);
-	bot_hp += GroupLeadershipAAHealthEnhancement();
-	bot_hp += (bot_hp * ((spellbonuses.MaxHPChange + itembonuses.MaxHPChange) / 10000.0f));
-	max_hp = bot_hp;
-	if (current_hp > max_hp)
+	int64 base_hp = (CalcBaseHP() + itembonuses.HP);
+	int64 nd = aabonuses.MaxHPChange + spellbonuses.MaxHPChange + itembonuses.MaxHPChange;
+	int64 max_hp = (base_hp * nd / 10000) + base_hp;
+	max_hp += GroupLeadershipAAHealthEnhancement();
+	max_hp += 5;
+	max_hp += GetHeroicSTA() * 10;
+	max_hp += aabonuses.HP + spellbonuses.HP;
+	if (current_hp > max_hp) {
 		current_hp = max_hp;
-
-	int hp_perc_cap = spellbonuses.HPPercCap[0];
-	if(hp_perc_cap) {
-		int curHP_cap = ((max_hp * hp_perc_cap) / 100);
-		if (current_hp > curHP_cap || (spellbonuses.HPPercCap[1] && current_hp > spellbonuses.HPPercCap[1]))
-			current_hp = curHP_cap;
 	}
+	int hp_perc_cap = spellbonuses.HPPercCap[SBIndex::RESOURCE_PERCENT_CAP];
+	if (hp_perc_cap) {
+		int curHP_cap = (max_hp * hp_perc_cap) / 100;
+		if (current_hp > curHP_cap || (spellbonuses.HPPercCap[SBIndex::RESOURCE_AMOUNT_CAP] && current_hp > spellbonuses.HPPercCap[SBIndex::RESOURCE_AMOUNT_CAP])) {
+
+			current_hp = curHP_cap;
+		}
+	}
+
+	this->max_hp = static_cast<int32>(
+		EQ::Clamp(max_hp, 
+			static_cast<int64>(0LL), 
+			static_cast<int64>(std::numeric_limits<int32>::max()))
+		);
+
 	return max_hp;
 }
 
diff --git a/zone/client_mods.cpp b/zone/client_mods.cpp
index 0490b87d3..451515675 100644
--- a/zone/client_mods.cpp
+++ b/zone/client_mods.cpp
@@ -315,26 +315,55 @@ int32 Client::CalcHPRegenCap()
 
 int32 Client::CalcMaxHP()
 {
-	int32 base_hp = (CalcBaseHP() + itembonuses.HP);
-	int32 nd = aabonuses.MaxHPChange + spellbonuses.MaxHPChange + itembonuses.MaxHPChange;
-	max_hp = (base_hp * nd / 10000) + base_hp;
-	max_hp += GroupLeadershipAAHealthEnhancement();
-	max_hp += 5;
-	max_hp += GetHeroicSTA() * 10;
-	max_hp += aabonuses.HP + spellbonuses.HP;
-	if (current_hp > max_hp) {
-		current_hp = max_hp;
-	}
-	int hp_perc_cap = spellbonuses.HPPercCap[SBIndex::RESOURCE_PERCENT_CAP];
-	if (hp_perc_cap) {
-		int curHP_cap = (max_hp * hp_perc_cap) / 100;
-		if (current_hp > curHP_cap || (spellbonuses.HPPercCap[SBIndex::RESOURCE_AMOUNT_CAP] && current_hp > spellbonuses.HPPercCap[SBIndex::RESOURCE_AMOUNT_CAP])) {
-
-			current_hp = curHP_cap;
+	if(RuleB(Character, FixHPCalculationOverflow)) {
+		int64 base_hp = (CalcBaseHP() + itembonuses.HP);
+		int64 nd = aabonuses.MaxHPChange + spellbonuses.MaxHPChange + itembonuses.MaxHPChange;
+		int64 max_hp = (base_hp * nd / 10000) + base_hp;
+		max_hp += GroupLeadershipAAHealthEnhancement();
+		max_hp += 5;
+		max_hp += GetHeroicSTA() * 10;
+		max_hp += aabonuses.HP + spellbonuses.HP;
+		if (current_hp > max_hp) {
+			current_hp = max_hp;
 		}
-	}
+		int hp_perc_cap = spellbonuses.HPPercCap[SBIndex::RESOURCE_PERCENT_CAP];
+		if (hp_perc_cap) {
+			int curHP_cap = (max_hp * hp_perc_cap) / 100;
+			if (current_hp > curHP_cap || (spellbonuses.HPPercCap[SBIndex::RESOURCE_AMOUNT_CAP] && current_hp > spellbonuses.HPPercCap[SBIndex::RESOURCE_AMOUNT_CAP])) {
 
-	return max_hp;
+				current_hp = curHP_cap;
+			}
+		}
+
+		this->max_hp = static_cast<int32>(
+			EQ::Clamp(max_hp, 
+				static_cast<int64>(0LL), 
+				static_cast<int64>(std::numeric_limits<int32>::max()))
+			);
+
+		return max_hp;
+	} else {
+		int32 base_hp = (CalcBaseHP() + itembonuses.HP);
+		int32 nd = aabonuses.MaxHPChange + spellbonuses.MaxHPChange + itembonuses.MaxHPChange;
+		max_hp = (base_hp * nd / 10000) + base_hp;
+		max_hp += GroupLeadershipAAHealthEnhancement();
+		max_hp += 5;
+		max_hp += GetHeroicSTA() * 10;
+		max_hp += aabonuses.HP + spellbonuses.HP;
+		if (current_hp > max_hp) {
+			current_hp = max_hp;
+		}
+		int hp_perc_cap = spellbonuses.HPPercCap[SBIndex::RESOURCE_PERCENT_CAP];
+		if (hp_perc_cap) {
+			int curHP_cap = (max_hp * hp_perc_cap) / 100;
+			if (current_hp > curHP_cap || (spellbonuses.HPPercCap[SBIndex::RESOURCE_AMOUNT_CAP] && current_hp > spellbonuses.HPPercCap[SBIndex::RESOURCE_AMOUNT_CAP])) {
+
+				current_hp = curHP_cap;
+			}
+		}
+
+		return max_hp;
+	}
 }
 
 uint32 Mob::GetClassLevelFactor()
diff --git a/zone/merc.cpp b/zone/merc.cpp
index 513e608d9..7a65d5ff7 100644
--- a/zone/merc.cpp
+++ b/zone/merc.cpp
@@ -17,6 +17,7 @@
 
 #include "../common/string_util.h"
 #include "../common/rulesys.h"
+#include "../common/data_verification.h"
 
 extern volatile bool is_zone_loaded;
 
@@ -843,23 +844,30 @@ int32 Merc::CalcHPRegenCap()
 }
 
 int32 Merc::CalcMaxHP() {
-	int32 base_hp = (CalcBaseHP() + itembonuses.HP);
-	int32 nd = aabonuses.MaxHPChange + spellbonuses.MaxHPChange + itembonuses.MaxHPChange;
-	max_hp = (base_hp * nd / 10000) + base_hp;
+	int64 base_hp = (CalcBaseHP() + itembonuses.HP);
+	int64 nd = aabonuses.MaxHPChange + spellbonuses.MaxHPChange + itembonuses.MaxHPChange;
+	int64 max_hp = (base_hp * nd / 10000) + base_hp;
 	max_hp += GroupLeadershipAAHealthEnhancement();
 	max_hp += 5;
 	max_hp += GetHeroicSTA() * 10;
 	max_hp += aabonuses.HP + spellbonuses.HP;
-
-	if (current_hp > max_hp)
+	if (current_hp > max_hp) {
 		current_hp = max_hp;
-
-	int hp_perc_cap = spellbonuses.HPPercCap[SBIndex::RESOURCE_PERCENT_CAP];
-	if(hp_perc_cap) {
-		int curHP_cap = (max_hp * hp_perc_cap) / 100;
-		if (current_hp > curHP_cap || (spellbonuses.HPPercCap[SBIndex::RESOURCE_AMOUNT_CAP] && current_hp > spellbonuses.HPPercCap[SBIndex::RESOURCE_AMOUNT_CAP]))
-			current_hp = curHP_cap;
 	}
+	int hp_perc_cap = spellbonuses.HPPercCap[SBIndex::RESOURCE_PERCENT_CAP];
+	if (hp_perc_cap) {
+		int curHP_cap = (max_hp * hp_perc_cap) / 100;
+		if (current_hp > curHP_cap || (spellbonuses.HPPercCap[SBIndex::RESOURCE_AMOUNT_CAP] && current_hp > spellbonuses.HPPercCap[SBIndex::RESOURCE_AMOUNT_CAP])) {
+
+			current_hp = curHP_cap;
+		}
+	}
+
+	this->max_hp = static_cast<int32>(
+		EQ::Clamp(max_hp, 
+			static_cast<int64>(0LL), 
+			static_cast<int64>(std::numeric_limits<int32>::max()))
+		);
 
 	return max_hp;
 }