diff --git a/modules/phoenix/cpp/chat_adjustments.cpp b/modules/phoenix/cpp/chat_adjustments.cpp
new file mode 100644
index 00000000000..4db70a646c7
--- /dev/null
+++ b/modules/phoenix/cpp/chat_adjustments.cpp
@@ -0,0 +1,154 @@
+/************************************************************************
+ * Chat Adjustments Module
+ *
+ * Phoenix chat rules, applied by catching the standard chat packet
+ * before the base handler. Each section below is one rule.
+ ************************************************************************/
+#include "common/earth_time.h"
+#include "common/ipc_structs.h"
+#include "common/logging.h"
+#include "map/entities/char_entity.h"
+#include "map/enums/chat_message_type.h"
+#include "map/enums/msg_std.h"
+#include "map/ipc_client.h"
+#include "map/packets/basic.h"
+#include "map/packets/c2s/0x0b5_chat_std.h"
+#include "map/packets/s2c/0x009_message.h"
+#include "map/packets/s2c/0x017_chat_std.h"
+#include "map/utils/moduleutils.h"
+#include "map/zone.h"
+
+#include <format>
+#include <string>
+#include <string_view>
+
+namespace
+{
+
+//-----------------------------------
+// Section: GM system messages.
+//-----------------------------------
+// A GM message starting with ### broadcasts the text after it to the whole
+// server. # and ## are refused with a hint, so a mistyped message cannot
+// broadcast. Players are not affected.
+
+constexpr std::string_view systemMessagePrefix = "###";
+
+const std::string systemMessageHint = "System messages start with ###.";
+
+// The base handler broadcasts any GM # message before it looks at the chat
+// kind. Every GM # message must be consumed here.
+auto handleSystemMessage(CCharEntity* PChar, const std::string& message) -> bool
+{
+    const auto body = message.starts_with(systemMessagePrefix) ? message.substr(systemMessagePrefix.size()) : std::string();
+
+    if (body.empty())
+    {
+        PChar->pushPacket<GP_SERV_COMMAND_CHAT_STD>(PChar, MESSAGE_SYSTEM_1, systemMessageHint);
+
+        return true;
+    }
+
+    message::send(ipc::ChatMessageServerMessage{
+        .senderId   = PChar->id,
+        .senderName = PChar->getName(),
+        .message    = body,
+        .zoneId     = PChar->getZone(),
+        .gmLevel    = PChar->m_GMlevel,
+    });
+
+    return true;
+}
+
+//-----------------------------------
+// Section: Yell restrictions.
+//-----------------------------------
+// Yell requires level 10 on some job. The cooldown is 10 minutes instead of
+// the base 30 seconds. Which zones allow yell at all is still the Yell flag
+// in zone_settings.misc.
+
+constexpr uint8 minYellLevel = 10;
+
+// The base handler's own 30 second cooldown expires inside this one.
+constexpr uint32 yellCooldown = 600;
+
+// Separate from the base handler's [YELL]Cooldown so the two do not fight.
+// Self-expires and persists through zoning.
+const std::string yellCooldownVar = "[YELL]CooldownPhx";
+
+auto handleYell(CCharEntity* PChar) -> bool
+{
+    // GMs are exempt. That also keeps their ! commands working through this
+    // channel. A zone without the Yell flag and a banned character both keep
+    // the base handler's own refusal. Neither burns the cooldown.
+    //
+    // Everyone else is caught before the base handler sees the message.
+    // An unresolved ! command from a non-GM falls through to the yell path there.
+    if (PChar->m_GMlevel > 0 ||
+        !PChar->loc.zone->CanUseMisc(xi::ZoneMisc::Yell) ||
+        PChar->getCharVar("[YELL]Banned") == 1)
+    {
+        return false;
+    }
+
+    // Level 10 on any job is enough. A level sync or a job change does not take yell away.
+    if (PChar->getHighestJobLevel() < minYellLevel)
+    {
+        PChar->pushPacket<GP_SERV_COMMAND_CHAT_STD>(PChar, MESSAGE_SYSTEM_1, std::format("You must reach level {} before you can use /yell.", minYellLevel));
+
+        return true;
+    }
+
+    if (PChar->getCharVar(yellCooldownVar) == 1)
+    {
+        PChar->pushPacket<GP_SERV_COMMAND_MESSAGE>(PChar, 0, MsgStd::WaitLonger);
+
+        return true;
+    }
+
+    // CharVar will self-expire and set to zero after the cooldown period.
+    // A ! command that resolves in yell mode burns this without a yell going
+    // out. The module cannot see whether the command resolved. Skipping !
+    // messages would let unresolved ones yell past the cooldown.
+    PChar->setCharVar(yellCooldownVar, 1, earth_time::timestamp() + yellCooldown);
+
+    return false;
+}
+
+} // namespace
+
+class ChatAdjustments : public CPPModule
+{
+    void OnInit() override
+    {
+    }
+
+    auto OnIncomingPacket(MapSession* PSession, CCharEntity* PChar, CBasicPacket& data) -> bool override
+    {
+        // Return if the packet isn't standard chat
+        if (data.getType() != static_cast<uint16>(GP_CLI_COMMAND_CHAT_STD::packetId))
+        {
+            return false;
+        }
+
+        const auto* packet = data.as<GP_CLI_COMMAND_CHAT_STD>();
+
+        // Same length math as the base handler. The message may not be NULL-terminated.
+        const auto messageLength = std::min<std::size_t>((packet->header.size * 4) - 0x6, sizeof(packet->Str));
+        const auto rawMessage    = asStringFromUntrustedSource(packet->Str, messageLength);
+
+        if (PChar->m_GMlevel > 0 && !rawMessage.empty() && rawMessage[0] == '#')
+        {
+            return handleSystemMessage(PChar, rawMessage);
+        }
+
+        if (static_cast<GP_CLI_COMMAND_CHAT_STD_KIND>(packet->Kind) == GP_CLI_COMMAND_CHAT_STD_KIND::Yell)
+        {
+            return handleYell(PChar);
+        }
+
+        return false;
+    }
+};
+
+REGISTER_CPP_MODULE(ChatAdjustments);