diff --git a/src/common/Common.h b/src/common/Common.h
index aadddb7b..61b4ce9c 100644
--- a/src/common/Common.h
+++ b/src/common/Common.h
@@ -557,7 +557,7 @@ namespace Common {
       SetTitle = 0x1F4,
 
       SetStatusIcon = 0x1F8,
-
+      LimitBreakGauge = 0x1F9, // Max level, amount, build type (chop sound), lb type(0=pve lb 1=pvp lb)
       SetHomepoint = 0x1FB,
       SetFavorite = 0x1FC,
       LearnTeleport = 0x1FD,
@@ -586,6 +586,12 @@ namespace Common {
 
       ToggleOrchestrionUnlock = 0x396,
       Dismount = 0x3a0
+
+      SetPvPState = 0x5E0, // param3 must be 6 to engage a duel (hardcoded in the client)
+      EndDuelSession = 0x5E1, // because someone went oob?
+      StartDuelCountdown = 0x5E2, // begins a countdown; also does some duel bgm thing.
+      StartDuel = 0x5E3, // actually all it does is set the challenger actor id;
+      DuelResultScreen = 0x5E4, // win/lose thing, also reset a target id just like what EndDuelSession does.
    };
 
    enum struct ChatType : uint16_t
diff --git a/src/common/Network/PacketDef/Ipcs.h b/src/common/Network/PacketDef/Ipcs.h
index 0925c62b..82af4c8c 100644
--- a/src/common/Network/PacketDef/Ipcs.h
+++ b/src/common/Network/PacketDef/Ipcs.h
@@ -164,6 +164,7 @@ namespace Packets {
       PrepareZoning              = 0x027C, // updated 4.2
       ActorGauge                 = 0x027D, // updated 4.2
 
+      DuelChallenge             = 0x0277, // 4.2; this is the responsible for opening an ui
       PerformNote                = 0x0286, // updated 4.2
 
       // Unknown IPC types that still need to be sent
diff --git a/src/common/Network/PacketDef/Zone/ServerZoneDef.h b/src/common/Network/PacketDef/Zone/ServerZoneDef.h
index a835386f..0a5fcd26 100644
--- a/src/common/Network/PacketDef/Zone/ServerZoneDef.h
+++ b/src/common/Network/PacketDef/Zone/ServerZoneDef.h
@@ -1363,6 +1363,18 @@ struct FFXIVIpcObjectDespawn : FFXIVIpcBasePacket<ObjectDespawn>
    uint8_t padding[7];
 };
 
+struct FFXIVIpcDuelChallenge : FFXIVIpcBasePacket<DuelChallenge>
+{
+   uint8_t otherClassJobId;
+   uint8_t otherLevel; // class job level
+   uint8_t challengeByYou; // 0 if the other challenges you, 1 if you challenges the other.
+   uint8_t otherItemLevel;
+
+   uint32_t otherActorId;
+
+   char otherName[32];
+};
+
 
 } /* Server */
 } /* Packets */
diff --git a/src/servers/sapphire_zone/Network/Handlers/ActionHandler.cpp b/src/servers/sapphire_zone/Network/Handlers/ActionHandler.cpp
index d099be24..48010f02 100644
--- a/src/servers/sapphire_zone/Network/Handlers/ActionHandler.cpp
+++ b/src/servers/sapphire_zone/Network/Handlers/ActionHandler.cpp
@@ -103,6 +103,10 @@ enum ClientTrigger
    CompanionActionUnlock = 0x6A6,
 
    OpenPerformInstrumentUI = 0x71C,
+
+   OpenDuelUI = 0x898, // Open a duel ui
+   DuelRequestResult = 0x899, // either accept/reject
+
 };
 
 void Core::Network::GameConnection::actionHandler( const Packets::GamePacket& inPacket,