diff --git a/client/src/block_assets.rs b/client/src/assets/block.rs
similarity index 81%
rename from client/src/block_assets.rs
rename to client/src/assets/block.rs
index 82ab4b2..e0c31fa 100644
--- a/client/src/block_assets.rs
+++ b/client/src/assets/block.rs
@@ -2,8 +2,8 @@ use bevy::prelude::*;
 use common::prelude::*;
 
 pub fn plugin(app: &mut App) {
-    app.add_observer(insert_block_visuals);
     app.load_resource::<BlockAssets>();
+    app.add_observer(insert_block_visuals);
 }
 
 #[derive(Resource, Asset, Reflect, Clone)]
@@ -25,14 +25,13 @@ impl FromWorld for BlockAssets {
     }
 }
 
-/// Observer which automatically inserts block visuals (mesh and
-/// material) when an entity has the `Block` component added to it.
 fn insert_block_visuals(
-    add: On<Add, Block>,
+    event: On<Add, Block>,
     mut commands: Commands,
     block_assets: Res<BlockAssets>,
 ) {
-    commands.entity(add.entity).insert((
+    let block = event.entity;
+    commands.entity(block).insert((
         Mesh3d(block_assets.mesh.clone()),
         MeshMaterial3d(block_assets.material.clone()),
     ));
diff --git a/client/src/assets/mod.rs b/client/src/assets/mod.rs
new file mode 100644
index 0000000..20b1d07
--- /dev/null
+++ b/client/src/assets/mod.rs
@@ -0,0 +1,13 @@
+//! Common module to handle asset loading and adding visual components
+//! (such as [`Mesh`]) to entities when they are spawned from the server.
+//!
+//! This doesn't mean this is the only place assets are loaded.
+//! For example UI related assets may be loaded in `ui` plugins.
+
+use bevy::prelude::*;
+
+mod block;
+
+pub fn plugin(app: &mut App) {
+    app.add_plugins(block::plugin);
+}
diff --git a/client/src/camera.rs b/client/src/camera.rs
index ca22da0..945b696 100644
--- a/client/src/camera.rs
+++ b/client/src/camera.rs
@@ -3,58 +3,6 @@ use std::f32::consts::TAU;
 use bevy::prelude::*;
 
 use bevy::input::mouse::AccumulatedMouseMotion;
-use bevy::window::{CursorGrabMode, CursorOptions};
-
-pub fn cursor_grab(
-    mut mouse_button_input: ResMut<ButtonInput<MouseButton>>,
-    key_input: Res<ButtonInput<KeyCode>>,
-    window: Single<(&mut Window, &mut CursorOptions)>,
-) {
-    let (mut window, mut cursor) = window.into_inner();
-
-    let is_grabbed = cursor.grab_mode != CursorGrabMode::None;
-    let request_grab = mouse_button_input.any_just_pressed([MouseButton::Left, MouseButton::Right]);
-    let request_ungrab = !window.focused || key_input.just_pressed(KeyCode::Escape);
-
-    if !is_grabbed && request_grab && !request_ungrab {
-        cursor.grab_mode = CursorGrabMode::Locked;
-
-        // To prevent other systems (such as `place_break_blocks`)
-        // from seeing the mouse button inputs, clear the state here.
-        mouse_button_input.clear();
-    }
-
-    if is_grabbed && request_ungrab && !request_grab {
-        cursor.grab_mode = CursorGrabMode::None;
-    }
-
-    if is_grabbed && !request_ungrab {
-        // Set the cursor position to the center of the window, so that when
-        // it is ungrabbed, it will reappear there. Because `is_grabbed` is
-        // not updated on grab, this block is delayed by one frame.
-        //
-        // On Wayland, since the cursor is locked into place, this only needs
-        // to be done once. Unfortunately, for some reason this doesn't work
-        // in the same frame as setting `grab_mode`, and would log an error.
-        //
-        // On X11, the cursor can't be locked into place, only confined to the
-        // window bounds, so we repeatedly move the cursor back to the center
-        // while it's grabbed.
-        //
-        // On the web, the cursor can be locked, but setting its position is
-        // not supported at all, so this would instead log a bunch of errors.
-        let center = window.resolution.size() / 2.;
-        #[cfg(not(target_family = "wasm"))] // skip on web
-        window.set_cursor_position(Some(center));
-    }
-
-    // Keep cursor visbility in sync with `grab_mode`.
-    cursor.visible = cursor.grab_mode == CursorGrabMode::None;
-}
-
-pub fn is_cursor_grabbed(cursor: Single<&CursorOptions>) -> bool {
-    cursor.grab_mode != CursorGrabMode::None
-}
 
 #[derive(Component, Debug)]
 pub struct CameraFreeLook {
@@ -106,43 +54,3 @@ pub fn camera_look(
     // Override the camera transform's rotation.
     transform.rotation = Quat::from_euler(EulerRot::ZYX, 0.0, look.yaw, look.pitch);
 }
-
-#[derive(Component)]
-pub struct Crosshair;
-
-pub fn setup_crosshair(mut commands: Commands, assets: Res<AssetServer>) {
-    commands.spawn((
-        Node {
-            width: percent(100),
-            height: percent(100),
-            align_items: AlignItems::Center,
-            justify_content: JustifyContent::Center,
-            ..default()
-        },
-        children![(
-            Crosshair,
-            Node {
-                width: px(64),
-                height: px(64),
-                ..default()
-            },
-            ImageNode {
-                image: assets.load("crosshair.png"),
-                ..default()
-            },
-            // Hidden by default, because cursor shouldn't be grabbed at startup either.
-            Visibility::Hidden,
-        )],
-    ));
-}
-
-pub fn update_crosshair_visibility(
-    cursor: Single<&CursorOptions, Changed<CursorOptions>>,
-    crosshair: Single<&mut Visibility, With<Crosshair>>,
-) {
-    let is_grabbed = cursor.grab_mode != CursorGrabMode::None;
-    let mut crosshair_visibility = crosshair.into_inner();
-    *crosshair_visibility = (!is_grabbed || cursor.visible)
-        .then_some(Visibility::Hidden)
-        .unwrap_or_default();
-}
diff --git a/client/src/input.rs b/client/src/input/client_inputs.rs
similarity index 89%
rename from client/src/input.rs
rename to client/src/input/client_inputs.rs
index 3f08e08..ad4b841 100644
--- a/client/src/input.rs
+++ b/client/src/input/client_inputs.rs
@@ -1,11 +1,14 @@
+//! Handles client-side input using [`lightyear`], updating the
+//! [`ActionState`] of the affected entities (such as the `Player`).
+
 use bevy::prelude::*;
+use common::prelude::*;
 use lightyear::prelude::input::client::*;
 use lightyear::prelude::input::native::*;
 
 use bevy::window::{CursorGrabMode, CursorOptions};
 
 use crate::camera::CameraFreeLook;
-use common::network::Inputs;
 
 pub fn plugin(app: &mut App) {
     app.add_systems(
diff --git a/client/src/input/cursor_grab.rs b/client/src/input/cursor_grab.rs
new file mode 100644
index 0000000..ffe3142
--- /dev/null
+++ b/client/src/input/cursor_grab.rs
@@ -0,0 +1,63 @@
+use bevy::prelude::*;
+
+use bevy::window::{CursorGrabMode, CursorOptions};
+
+use crate::Screen;
+
+pub fn plugin(app: &mut App) {
+    app.add_systems(
+        PreUpdate,
+        update_cursor_grab.run_if(in_state(Screen::Gameplay)),
+    );
+}
+
+fn update_cursor_grab(
+    mut mouse_button_input: ResMut<ButtonInput<MouseButton>>,
+    key_input: Res<ButtonInput<KeyCode>>,
+    window: Single<(&mut Window, &mut CursorOptions)>,
+) {
+    let (mut window, mut cursor) = window.into_inner();
+
+    let is_grabbed = cursor.grab_mode != CursorGrabMode::None;
+    let request_grab = mouse_button_input.any_just_pressed([MouseButton::Left, MouseButton::Right]);
+    let request_ungrab = !window.focused || key_input.just_pressed(KeyCode::Escape);
+
+    if !is_grabbed && request_grab && !request_ungrab {
+        cursor.grab_mode = CursorGrabMode::Locked;
+
+        // To prevent other systems (such as `place_break_blocks`)
+        // from seeing the mouse button inputs, clear the state here.
+        mouse_button_input.clear();
+    }
+
+    if is_grabbed && request_ungrab && !request_grab {
+        cursor.grab_mode = CursorGrabMode::None;
+    }
+
+    if is_grabbed && !request_ungrab {
+        // Set the cursor position to the center of the window, so that when
+        // it is ungrabbed, it will reappear there. Because `is_grabbed` is
+        // not updated on grab, this block is delayed by one frame.
+        //
+        // On Wayland, since the cursor is locked into place, this only needs
+        // to be done once. Unfortunately, for some reason this doesn't work
+        // in the same frame as setting `grab_mode`, and would log an error.
+        //
+        // On X11, the cursor can't be locked into place, only confined to the
+        // window bounds, so we repeatedly move the cursor back to the center
+        // while it's grabbed.
+        //
+        // On the web, the cursor can be locked, but setting its position is
+        // not supported at all, so this would instead log a bunch of errors.
+        let center = window.resolution.size() / 2.;
+        #[cfg(not(target_family = "wasm"))] // skip on web
+        window.set_cursor_position(Some(center));
+    }
+
+    // Keep cursor visbility in sync with `grab_mode`.
+    cursor.visible = cursor.grab_mode == CursorGrabMode::None;
+}
+
+pub fn is_cursor_grabbed(cursor: Single<&CursorOptions>) -> bool {
+    cursor.grab_mode != CursorGrabMode::None
+}
diff --git a/client/src/input/mod.rs b/client/src/input/mod.rs
new file mode 100644
index 0000000..d3fa23a
--- /dev/null
+++ b/client/src/input/mod.rs
@@ -0,0 +1,10 @@
+use bevy::prelude::*;
+
+mod client_inputs;
+mod cursor_grab;
+
+pub use cursor_grab::is_cursor_grabbed;
+
+pub fn plugin(app: &mut App) {
+    app.add_plugins((client_inputs::plugin, cursor_grab::plugin));
+}
diff --git a/client/src/main.rs b/client/src/main.rs
index baac5c9..8280f32 100644
--- a/client/src/main.rs
+++ b/client/src/main.rs
@@ -9,16 +9,18 @@ use lightyear::prelude::input::native::InputMarker;
 use lightyear::prelude::server::Started;
 
 mod args;
-mod block_assets;
+mod assets;
 mod camera;
 mod input;
-mod loading;
 mod placement;
+mod ui;
 
 use args::*;
 use camera::*;
 use placement::*;
 
+use input::is_cursor_grabbed;
+
 #[derive(States, Clone, Copy, PartialEq, Eq, Hash, Debug)]
 pub enum Screen {
     Loading,
@@ -26,6 +28,7 @@ pub enum Screen {
 }
 
 fn main() -> Result {
+    let args = Args::parse();
     let mut app = App::new();
 
     app.add_plugins(
@@ -53,32 +56,23 @@ fn main() -> Result {
 
     app.add_plugins((
         bevy_fix_cursor_unlock_web::FixPointerUnlockPlugin,
-        ServerPlugin,
-        ClientPlugin,
         common::asset_loading::plugin,
-        block_assets::plugin,
-        loading::plugin,
+        common::network::plugin,
+        assets::plugin,
         input::plugin,
+        ui::plugin,
     ));
 
-    app.insert_resource(Args::parse());
+    app.insert_resource(args);
     app.insert_state(Screen::Loading);
 
     app.add_systems(
         OnEnter(Screen::Gameplay),
-        (setup_crosshair, setup_scene, start_server_or_connect),
+        (setup_scene, start_server_or_connect),
     );
 
-    // TODO: Create and configure `SystemSet`s for gameplay, input, etc.
-    app.add_systems(
-        Update,
-        (
-            cursor_grab,
-            update_crosshair_visibility.after(cursor_grab),
-            camera_look.after(cursor_grab).run_if(is_cursor_grabbed),
-        )
-            .run_if(in_state(Screen::Gameplay)),
-    );
+    // TODO: Create and configure `SystemSet`s for gameplay, etc.
+    app.add_systems(Update, camera_look.run_if(is_cursor_grabbed));
 
     // `place_break_blocks` requires the camera's `GlobalTransform`.
     // For a most up-to-date value, run it after that's been updated.
@@ -90,7 +84,7 @@ fn main() -> Result {
     );
 
     app.add_observer(spawn_initial_blocks);
-    app.add_observer(handle_predicted_spawn);
+    app.add_observer(handle_predicted_player_spawn);
 
     app.run();
     Ok(())
@@ -136,7 +130,7 @@ fn spawn_initial_blocks(_event: On<Add, Started>, mut blocks: Blocks) {
 }
 
 /// When the `Predicted` player we control is being spawned, insert necessary components.
-fn handle_predicted_spawn(event: On<Add, Predicted>, mut commands: Commands) {
+fn handle_predicted_player_spawn(event: On<Add, Predicted>, mut commands: Commands) {
     let player = event.entity;
     commands
         .entity(player)
diff --git a/client/src/ui/crosshair.rs b/client/src/ui/crosshair.rs
new file mode 100644
index 0000000..9ba8c53
--- /dev/null
+++ b/client/src/ui/crosshair.rs
@@ -0,0 +1,68 @@
+use bevy::prelude::*;
+use common::prelude::*;
+
+use bevy::window::{CursorGrabMode, CursorOptions};
+
+use crate::Screen;
+
+pub fn plugin(app: &mut App) {
+    app.load_resource::<CrosshairAssets>();
+    app.add_systems(OnEnter(Screen::Gameplay), setup_crosshair);
+    app.add_systems(Update, update_crosshair_visibility);
+}
+
+#[derive(Resource, Asset, Reflect, Clone)]
+#[reflect(Resource)]
+pub struct CrosshairAssets {
+    #[dependency]
+    image: Handle<Image>,
+}
+
+impl FromWorld for CrosshairAssets {
+    fn from_world(world: &mut World) -> Self {
+        let assets = world.resource::<AssetServer>();
+        Self {
+            image: assets.load("crosshair.png"),
+        }
+    }
+}
+
+#[derive(Component)]
+pub struct Crosshair;
+
+fn setup_crosshair(mut commands: Commands, assets: Res<CrosshairAssets>) {
+    commands.spawn((
+        Node {
+            width: percent(100),
+            height: percent(100),
+            align_items: AlignItems::Center,
+            justify_content: JustifyContent::Center,
+            ..default()
+        },
+        children![(
+            Crosshair,
+            Node {
+                width: px(64),
+                height: px(64),
+                ..default()
+            },
+            ImageNode {
+                image: assets.image.clone(),
+                ..default()
+            },
+            // Hidden by default, because cursor shouldn't be grabbed at startup either.
+            Visibility::Hidden,
+        )],
+    ));
+}
+
+fn update_crosshair_visibility(
+    cursor: Single<&CursorOptions, Changed<CursorOptions>>,
+    crosshair: Single<&mut Visibility, With<Crosshair>>,
+) {
+    let is_grabbed = cursor.grab_mode != CursorGrabMode::None;
+    let mut crosshair_visibility = crosshair.into_inner();
+    *crosshair_visibility = (!is_grabbed || cursor.visible)
+        .then_some(Visibility::Hidden)
+        .unwrap_or_default();
+}
diff --git a/client/src/loading.rs b/client/src/ui/loading_screen.rs
similarity index 100%
rename from client/src/loading.rs
rename to client/src/ui/loading_screen.rs
diff --git a/client/src/ui/mod.rs b/client/src/ui/mod.rs
new file mode 100644
index 0000000..b852000
--- /dev/null
+++ b/client/src/ui/mod.rs
@@ -0,0 +1,8 @@
+use bevy::prelude::*;
+
+mod crosshair;
+mod loading_screen;
+
+pub fn plugin(app: &mut App) {
+    app.add_plugins((crosshair::plugin, loading_screen::plugin));
+}
diff --git a/common/src/lib.rs b/common/src/lib.rs
index 6a57afa..53ab0ac 100644
--- a/common/src/lib.rs
+++ b/common/src/lib.rs
@@ -3,13 +3,13 @@ pub mod block;
 pub mod network;
 pub mod player;
 
-// This is mostly just re-exporting everything for now, but in the future,
-// we might want to select exactly what's exposed by the `prelude` module.
 pub mod prelude {
-    pub use super::network;
+    pub use crate::network;
 
-    pub use super::block::*;
-    pub use super::player::*;
+    pub use crate::block::*;
+    pub use crate::network::protocol::*;
+    pub use crate::player::*;
 
-    pub use super::asset_loading::LoadResource;
+    // Allows use of the `App::load_resource` extension trait function.
+    pub use crate::asset_loading::LoadResource;
 }
diff --git a/common/src/network/client.rs b/common/src/network/client.rs
index 5c84add..21eecc7 100644
--- a/common/src/network/client.rs
+++ b/common/src/network/client.rs
@@ -2,23 +2,13 @@ use bevy::prelude::*;
 use lightyear::prelude::client::*;
 use lightyear::prelude::*;
 
-pub use super::client_webtransport::ConnectWebTransportCommand;
+pub(super) fn plugin(app: &mut App) {
+    app.add_plugins(ClientPlugins::default());
 
-pub struct ClientPlugin;
+    app.add_observer(on_connected);
+    app.add_observer(on_disconnected);
 
-impl Plugin for ClientPlugin {
-    fn build(&self, app: &mut App) {
-        app.add_plugins(ClientPlugins::default());
-
-        if !app.is_plugin_added::<super::ProtocolPlugin>() {
-            app.add_plugins(super::ProtocolPlugin);
-        }
-
-        app.add_observer(on_connected);
-        app.add_observer(on_disconnected);
-
-        app.add_observer(autoconnect_host_client);
-    }
+    app.add_observer(autoconnect_host_client);
 }
 
 /// Automatically creates a "host client" to connect to the local server when it is started.
diff --git a/common/src/network/mod.rs b/common/src/network/mod.rs
index c621989..1120010 100644
--- a/common/src/network/mod.rs
+++ b/common/src/network/mod.rs
@@ -1,12 +1,19 @@
-mod client;
-mod protocol;
-mod server;
+use bevy::prelude::*;
+
+pub(crate) mod protocol;
 
+mod client;
 mod client_webtransport;
+mod server;
 mod server_webtransport;
 
-pub use client::*;
-pub use protocol::*;
-pub use server::*;
+pub use crate::network::client_webtransport::ConnectWebTransportCommand;
+pub use crate::network::server::StartLocalServerCommand;
+#[cfg(not(target_family = "wasm"))]
+pub use crate::network::server_webtransport::StartWebTransportServerCommand;
 
 pub const DEFAULT_PORT: u16 = 13580;
+
+pub fn plugin(app: &mut App) {
+    app.add_plugins((protocol::plugin, client::plugin, server::plugin));
+}
diff --git a/common/src/network/protocol.rs b/common/src/network/protocol.rs
index 4c26c96..40b730c 100644
--- a/common/src/network/protocol.rs
+++ b/common/src/network/protocol.rs
@@ -8,6 +8,21 @@ use serde::{Deserialize, Serialize};
 use crate::block::Block;
 use crate::player::Player;
 
+pub(super) fn plugin(app: &mut App) {
+    app.add_plugins(InputPlugin::<Inputs>::default());
+
+    // marker components
+    app.register_component::<Player>();
+    app.register_component::<Block>();
+
+    app.register_component::<Transform>()
+        .add_prediction()
+        .add_interpolation_with(interpolate_transform);
+
+    // unified update systems
+    app.add_systems(FixedUpdate, crate::player::movement);
+}
+
 #[derive(Default, Deserialize, Serialize, Reflect, Clone, PartialEq, Debug)]
 pub struct Inputs {
     pub movement: Vec2,
@@ -19,25 +34,6 @@ impl MapEntities for Inputs {
     fn map_entities<E: EntityMapper>(&mut self, _entity_mapper: &mut E) {}
 }
 
-pub struct ProtocolPlugin;
-
-impl Plugin for ProtocolPlugin {
-    fn build(&self, app: &mut App) {
-        app.add_plugins(InputPlugin::<Inputs>::default());
-
-        // marker components
-        app.register_component::<Player>();
-        app.register_component::<Block>();
-
-        app.register_component::<Transform>()
-            .add_prediction()
-            .add_interpolation_with(interpolate_transform);
-
-        // unified update systems
-        app.add_systems(FixedUpdate, crate::player::movement);
-    }
-}
-
 fn interpolate_transform(start: Transform, other: Transform, t: f32) -> Transform {
     Transform {
         translation: start.translation.lerp(other.translation, t),
diff --git a/common/src/network/server.rs b/common/src/network/server.rs
index 58b26b5..41eeb78 100644
--- a/common/src/network/server.rs
+++ b/common/src/network/server.rs
@@ -4,29 +4,18 @@ use lightyear::prelude::*;
 
 use crate::player::Player;
 
-#[cfg(not(target_family = "wasm"))]
-pub use super::server_webtransport::StartWebTransportServerCommand;
+pub(super) fn plugin(app: &mut App) {
+    app.add_plugins(ServerPlugins::default());
 
-pub struct ServerPlugin;
+    // TODO: See what happens when we try to start a server, but it
+    //       can't, for example due to the port already being in use.
+    app.add_observer(on_server_started);
+    app.add_observer(on_server_stopped);
+    app.add_observer(handle_client_connected);
+    app.add_observer(handle_client_disconnected);
 
-impl Plugin for ServerPlugin {
-    fn build(&self, app: &mut App) {
-        app.add_plugins(ServerPlugins::default());
-
-        if !app.is_plugin_added::<super::ProtocolPlugin>() {
-            app.add_plugins(super::ProtocolPlugin);
-        }
-
-        // TODO: See what happens when we try to start a server, but it
-        //       can't, for example due to the port already being in use.
-        app.add_observer(on_server_started);
-        app.add_observer(on_server_stopped);
-        app.add_observer(handle_client_connected);
-        app.add_observer(handle_client_disconnected);
-
-        #[cfg(not(target_family = "wasm"))]
-        app.add_observer(super::server_webtransport::print_certificate_digest);
-    }
+    #[cfg(not(target_family = "wasm"))]
+    app.add_observer(super::server_webtransport::print_certificate_digest);
 }
 
 /// Starts a local-only server that only a host-client can connect to.
diff --git a/common/src/player.rs b/common/src/player.rs
index 4e24d58..bace3e3 100644
--- a/common/src/player.rs
+++ b/common/src/player.rs
@@ -4,7 +4,7 @@ use lightyear::prelude::*;
 use lightyear::prelude::input::native::ActionState;
 use serde::{Deserialize, Serialize};
 
-use crate::network::Inputs;
+use crate::network::protocol::Inputs;
 
 const MOVEMENT_SPEED: f32 = 5.0;