diff --git a/lighthouse-protocol/src/input/input_event.rs b/lighthouse-protocol/src/input/input_event.rs
index c581da3..3adf521 100644
--- a/lighthouse-protocol/src/input/input_event.rs
+++ b/lighthouse-protocol/src/input/input_event.rs
@@ -2,7 +2,7 @@ use serde::{Deserialize, Serialize};
 
 use crate::Direction;
 
-use super::{EventSource, GamepadEvent, KeyEvent, MidiEvent, MouseEvent, OrientationEvent, UnknownEvent};
+use super::{EventSource, GamepadEvent, KeyEvent, MidiEvent, MotionEvent, MouseEvent, OrientationEvent, UnknownEvent};
 
 /// A user input event, as generated by the new frontend (LUNA).
 #[derive(Debug, Serialize, Deserialize, PartialEq, Clone)]
@@ -13,6 +13,7 @@ pub enum InputEvent {
     Gamepad(GamepadEvent),
     Midi(MidiEvent),
     Orientation(OrientationEvent),
+    Motion(MotionEvent),
     #[serde(untagged)]
     Unknown(UnknownEvent),
 }
@@ -25,6 +26,7 @@ impl InputEvent {
             InputEvent::Mouse(MouseEvent { source, .. }) => source,
             InputEvent::Gamepad(GamepadEvent { source, .. }) => source,
             InputEvent::Orientation(OrientationEvent { source, .. }) => source,
+            InputEvent::Motion(MotionEvent { source, .. }) => source,
             InputEvent::Midi(MidiEvent { source, .. }) => source,
             InputEvent::Unknown(UnknownEvent { source, .. }) => source,
         }
diff --git a/lighthouse-protocol/src/input/mod.rs b/lighthouse-protocol/src/input/mod.rs
index a0435bc..05fca69 100644
--- a/lighthouse-protocol/src/input/mod.rs
+++ b/lighthouse-protocol/src/input/mod.rs
@@ -9,6 +9,7 @@ mod key_event;
 mod key_modifiers;
 mod legacy_input_event;
 mod midi_event;
+mod motion_event;
 mod mouse_button;
 mod mouse_event;
 mod orientation_event;
@@ -25,6 +26,7 @@ pub use key_event::*;
 pub use key_modifiers::*;
 pub use legacy_input_event::*;
 pub use midi_event::*;
+pub use motion_event::*;
 pub use mouse_button::*;
 pub use mouse_event::*;
 pub use orientation_event::*;
diff --git a/lighthouse-protocol/src/input/motion_event.rs b/lighthouse-protocol/src/input/motion_event.rs
new file mode 100644
index 0000000..2bfc132
--- /dev/null
+++ b/lighthouse-protocol/src/input/motion_event.rs
@@ -0,0 +1,21 @@
+use serde::{Deserialize, Serialize};
+
+use crate::{Rot3, Vec3};
+
+use super::EventSource;
+
+/// A device motion event.
+#[derive(Debug, Serialize, Deserialize, PartialEq, Clone)]
+#[serde(rename_all = "camelCase")]
+pub struct MotionEvent {
+    /// The client identifier.
+    pub source: EventSource,
+    /// The acceleration in 3D space in m/s^2.
+    pub acceleration: Option<Vec3<Option<f64>>>,
+    /// The acceleration in 3D space (including gravity) in m/s^2.
+    pub acceleration_including_gravity: Option<Vec3<Option<f64>>>,
+    /// The rotation rate in deg/s on the three rotation axes.
+    pub rotation_rate: Option<Rot3<Option<f64>>>,
+    /// The granularity of these events in ms.
+    pub interval: f64,
+}
diff --git a/lighthouse-protocol/src/input/orientation_event.rs b/lighthouse-protocol/src/input/orientation_event.rs
index 8aa748d..8650a69 100644
--- a/lighthouse-protocol/src/input/orientation_event.rs
+++ b/lighthouse-protocol/src/input/orientation_event.rs
@@ -4,6 +4,7 @@ use super::EventSource;
 
 /// A device orientation event.
 #[derive(Debug, Serialize, Deserialize, PartialEq, Clone)]
+#[serde(rename_all = "camelCase")]
 pub struct OrientationEvent {
     /// The client identifier.
     pub source: EventSource,
diff --git a/lighthouse-protocol/src/utils/mod.rs b/lighthouse-protocol/src/utils/mod.rs
index 822bd4d..eda8e67 100644
--- a/lighthouse-protocol/src/utils/mod.rs
+++ b/lighthouse-protocol/src/utils/mod.rs
@@ -2,18 +2,22 @@ mod color;
 mod direction;
 mod rect;
 mod rem_euclid;
+mod rot3;
 mod rotation;
 mod sqrt;
 mod unity;
 mod vec2;
+mod vec3;
 mod zero;
 
 pub use color::*;
 pub use direction::*;
 pub use rect::*;
 pub use rem_euclid::*;
+pub use rot3::*;
 pub use rotation::*;
 pub use sqrt::*;
 pub use unity::*;
 pub use vec2::*;
+pub use vec3::*;
 pub use zero::*;
diff --git a/lighthouse-protocol/src/utils/rot3.rs b/lighthouse-protocol/src/utils/rot3.rs
new file mode 100644
index 0000000..5a82b91
--- /dev/null
+++ b/lighthouse-protocol/src/utils/rot3.rs
@@ -0,0 +1,32 @@
+use serde::{Deserialize, Serialize};
+
+use super::Zero;
+
+/// A 3D rotation.
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, Serialize, Deserialize)]
+pub struct Rot3<T> {
+    pub alpha: T,
+    pub beta: T,
+    pub gamma: T,
+}
+
+impl<T> Rot3<T> {
+    /// Creates a mew position.
+    pub const fn new(alpha: T, beta: T, gamma: T) -> Self {
+        Self { alpha, beta, gamma }
+    }
+
+    /// Maps a function over the vector.
+    pub fn map<U>(self, mut f: impl FnMut(T) -> U) -> Rot3<U> {
+        Rot3 {
+            alpha: f(self.alpha),
+            beta: f(self.beta),
+            gamma: f(self.gamma),
+        }
+    }
+}
+
+impl<T> Zero for Rot3<T> where T: Zero {
+    /// The origin.
+    const ZERO: Self = Self::new(T::ZERO, T::ZERO, T::ZERO);
+}
diff --git a/lighthouse-protocol/src/utils/vec3.rs b/lighthouse-protocol/src/utils/vec3.rs
new file mode 100644
index 0000000..364449b
--- /dev/null
+++ b/lighthouse-protocol/src/utils/vec3.rs
@@ -0,0 +1,87 @@
+use std::{fmt, ops::{Add, AddAssign, Mul, Neg, Sub, SubAssign}};
+
+use serde::{Deserialize, Serialize};
+
+use super::{Sqrt, Zero};
+
+/// A 3D vector.
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, Serialize, Deserialize)]
+pub struct Vec3<T> {
+    pub x: T,
+    pub y: T,
+    pub z: T,
+}
+
+impl<T> Vec3<T> {
+    /// Creates a mew position.
+    pub const fn new(x: T, y: T, z: T) -> Self {
+        Self { x, y, z }
+    }
+
+    /// Maps a function over the vector.
+    pub fn map<U>(self, mut f: impl FnMut(T) -> U) -> Vec3<U> {
+        Vec3 {
+            x: f(self.x),
+            y: f(self.y),
+            z: f(self.z),
+        }
+    }
+}
+
+impl<T> Zero for Vec3<T> where T: Zero {
+    /// The origin.
+    const ZERO: Self = Self::new(T::ZERO, T::ZERO, T::ZERO);
+}
+
+impl<T> Vec3<T> where T: Add<Output = T> + Mul<Output = T> + Sqrt + Copy {
+    /// The vector's length.
+    pub fn length(&self) -> T {
+        (self.x * self.x + self.y * self.y + self.z * self.z).sqrt()
+    }
+}
+
+impl<T> fmt::Display for Vec3<T> where T: fmt::Display {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "({}, {}, {})", self.x, self.y, self.z)
+    }
+}
+
+impl<T> Add for Vec3<T> where T: Add<Output = T> {
+    type Output = Self;
+
+    fn add(self, rhs: Vec3<T>) -> Self {
+        Self::new(self.x + rhs.x, self.y + rhs.y, self.z + rhs.z)
+    }
+}
+
+impl<T> Neg for Vec3<T> where T: Neg<Output = T> {
+    type Output = Self;
+
+    fn neg(self) -> Self {
+        Self::new(-self.x, -self.y, -self.z)
+    }
+}
+
+impl<T> Sub for Vec3<T> where T: Sub<Output = T> {
+    type Output = Self;
+
+    fn sub(self, rhs: Vec3<T>) -> Self {
+        Self::new(self.x - rhs.x, self.y - rhs.y, self.z - rhs.z)
+    }
+}
+
+impl<T> AddAssign<Self> for Vec3<T> where T: AddAssign<T> {
+    fn add_assign(&mut self, rhs: Vec3<T>) {
+        self.x += rhs.x;
+        self.y += rhs.y;
+        self.z += rhs.z;
+    }
+}
+
+impl<T> SubAssign<Self> for Vec3<T> where T: SubAssign<T> {
+    fn sub_assign(&mut self, rhs: Vec3<T>) {
+        self.x -= rhs.x;
+        self.y -= rhs.y;
+        self.z -= rhs.z;
+    }
+}