diff --git a/common/src/main/scala/net/psforever/packet/GamePacketOpcode.scala b/common/src/main/scala/net/psforever/packet/GamePacketOpcode.scala
index b0ab76a7f..342b80915 100644
--- a/common/src/main/scala/net/psforever/packet/GamePacketOpcode.scala
+++ b/common/src/main/scala/net/psforever/packet/GamePacketOpcode.scala
@@ -415,7 +415,7 @@ object GamePacketOpcode extends Enumeration {
 
     // OPCODES 0x50-5f
     case 0x50 => game.TargetingInfoMessage.decode
-    case 0x51 => noDecoder(TriggerEffectMessage)
+    case 0x51 => game.TriggerEffectMessage.decode
     case 0x52 => game.WeaponDryFireMessage.decode
     case 0x53 => noDecoder(DroppodLaunchRequestMessage)
     case 0x54 => noDecoder(HackMessage)
diff --git a/common/src/main/scala/net/psforever/packet/game/TriggerEffectMessage.scala b/common/src/main/scala/net/psforever/packet/game/TriggerEffectMessage.scala
new file mode 100644
index 000000000..a8c2cc9be
--- /dev/null
+++ b/common/src/main/scala/net/psforever/packet/game/TriggerEffectMessage.scala
@@ -0,0 +1,83 @@
+// Copyright (c) 2017 PSForever
+package net.psforever.packet.game
+
+import net.psforever.packet.{GamePacketOpcode, Marshallable, PacketHelpers, PlanetSideGamePacket}
+import net.psforever.types.Vector3
+import scodec.Codec
+import scodec.codecs._
+
+/**
+  * na
+  * @param unk1 na;
+  *             `true` to apply the effect usually
+  * @param unk2 na
+  */
+final case class TriggeredEffect(unk1 : Boolean,
+                                 unk2 : Long)
+
+/**
+  * Activate an effect that is not directly associated with an existing game object.
+  * Without a game object from which to inherit position and orientation, those explicit parameters must be provided.
+  * @param pos the position in the game world
+  * @param roll the amount of roll that affects orientation
+  * @param pitch the amount of pitch that affects orientation
+  * @param yaw the amount of yaw that affects orientation
+  */
+final case class TriggeredEffectLocation(pos : Vector3,
+                                         roll : Int,
+                                         pitch : Int,
+                                         yaw : Int)
+
+/**
+  * Dispatched by the server to cause a client to display a special graphical effect.<br>
+  * <br>
+  * The effect being triggered can be based around a specific game object or replayed freely, absent of an anchoring object.
+  * If object-based then the kinds of effects that can be activated are specific to the object.
+  * If unbound, then a wider range of effects can be displayed.
+  * Regardless, one category will rarely ever be activated under the same valid conditions of the other category.
+  * For example, the effect "on" will only work on objects that accept "on" normally, like a deployed `motionalarmsensor`.
+  * The effect "spawn_object_effect" can be applied anywhere in the environment;
+  * but, it can not be activated in conjunction with an existing object.
+  * @param obj an object that accepts the effect
+  * @param effect the name of the effect
+  * @param unk na;
+  *            when activating an effect on an existing object
+  * @param location an optional position where the effect will be displayed;
+  *                 when activating an effect independently
+  */
+final case class TriggerEffectMessage(obj : PlanetSideGUID,
+                                      effect : String,
+                                      unk : Option[TriggeredEffect] = None,
+                                      location : Option[TriggeredEffectLocation] = None
+                                     ) extends PlanetSideGamePacket {
+  type Packet = TriggerEffectMessage
+  def opcode = GamePacketOpcode.TriggerEffectMessage
+  def encode = TriggerEffectMessage.encode(this)
+}
+
+object TriggerEffectMessage extends Marshallable[TriggerEffectMessage] {
+  /**
+    * A `Codec` for `TriggeredEffect` data.
+    */
+  private val effect_codec : Codec[TriggeredEffect] = (
+    ("unk1" | bool) ::
+      ("unk2" | uint32L)
+  ).as[TriggeredEffect]
+
+  /**
+    * A `Codec` for `TriggeredEffectLocation` data.
+    */
+  private val effect_location_codec : Codec[TriggeredEffectLocation] = (
+    ("pos" | Vector3.codec_pos) ::
+      ("roll" | uint8L) ::
+      ("pitch" | uint8L) ::
+      ("yaw" | uint8L)
+  ).as[TriggeredEffectLocation]
+
+  implicit val codec : Codec[TriggerEffectMessage] = (
+    ("obj" | PlanetSideGUID.codec) >>:~ { obj =>
+      ("effect" | PacketHelpers.encodedString) ::
+      optional(bool, "unk" | effect_codec) ::
+      conditional(obj.guid == 0, "location" | effect_location_codec)
+    }).as[TriggerEffectMessage]
+}
diff --git a/common/src/test/scala/game/TriggerEffectMessageTest.scala b/common/src/test/scala/game/TriggerEffectMessageTest.scala
new file mode 100644
index 000000000..9e3e6faa5
--- /dev/null
+++ b/common/src/test/scala/game/TriggerEffectMessageTest.scala
@@ -0,0 +1,73 @@
+// Copyright (c) 2017 PSForever
+package game
+
+import org.specs2.mutable._
+import net.psforever.packet._
+import net.psforever.packet.game._
+import net.psforever.types.Vector3
+import scodec.bits._
+
+class TriggerEffectMessageTest extends Specification {
+  val string_motionalarmsensor = hex"51 970B 82 6F6E FA00C00000"
+  val string_boomer = hex"51 0000 93 737061776E5F6F626A6563745F656666656374 417BB2CB3B4F8E00000000"
+
+  "decode (motion alarm sensor)" in {
+    PacketCoding.DecodePacket(string_motionalarmsensor).require match {
+      case TriggerEffectMessage(guid, effect, unk, location) =>
+        guid mustEqual PlanetSideGUID(2967)
+        effect mustEqual "on"
+        unk.isDefined mustEqual true
+        unk.get.unk1 mustEqual true
+        unk.get.unk2 mustEqual 1000L
+        location.isDefined mustEqual false
+      case _ =>
+        ko
+    }
+  }
+
+  "decode (boomer)" in {
+    PacketCoding.DecodePacket(string_boomer).require match {
+      case TriggerEffectMessage(guid, effect, unk, location) =>
+        guid mustEqual PlanetSideGUID(0)
+        effect mustEqual "spawn_object_effect"
+        unk.isDefined mustEqual false
+        location.isDefined mustEqual true
+        location.get.pos.x mustEqual 3567.0156f
+        location.get.pos.y mustEqual 3278.6953f
+        location.get.pos.z mustEqual 114.484375f
+        location.get.roll mustEqual 0
+        location.get.pitch mustEqual 0
+        location.get.yaw mustEqual 0
+      case _ =>
+        ko
+    }
+  }
+
+  "encode (motion alarm sensor)" in {
+    val msg = TriggerEffectMessage(
+      PlanetSideGUID(2967),
+      "on",
+      Some(TriggeredEffect(true, 1000L)),
+      None
+    )
+    val pkt = PacketCoding.EncodePacket(msg).require.toByteVector
+
+    pkt mustEqual string_motionalarmsensor
+  }
+
+  "encode (boomer)" in {
+    val msg = TriggerEffectMessage(
+      PlanetSideGUID(0),
+      "spawn_object_effect",
+      None,
+      Some(TriggeredEffectLocation(
+        Vector3(3567.0156f, 3278.6953f, 114.484375f),
+        0, 0, 0
+      ))
+    )
+    val pkt = PacketCoding.EncodePacket(msg).require.toByteVector
+
+    pkt mustEqual string_boomer
+  }
+}
+