diff --git a/Makefile b/Makefile
index b8836cd..dff0d92 100644
--- a/Makefile
+++ b/Makefile
@@ -20,4 +20,10 @@ fmt:
 fix: fmt
 	cargo fix --allow-dirty --allow-staged
 
-.phony: run-pi clean check run fmt fix lint
\ No newline at end of file
+docs:
+	cargo doc
+
+open-docs:
+	cargo doc --open
+
+.phony: run-pi clean check run fmt fix lint docs open-docs
\ No newline at end of file
diff --git a/src/ai.rs b/src/ai.rs
index 9a93bed..3b1c2fe 100644
--- a/src/ai.rs
+++ b/src/ai.rs
@@ -1,3 +1,5 @@
+//! Systems for making NPCs come to life
+
 mod adjacent_ai_system;
 mod approach_ai_system;
 mod chase_ai_system;
diff --git a/src/camera.rs b/src/camera.rs
index 2e6b539..4437f04 100644
--- a/src/camera.rs
+++ b/src/camera.rs
@@ -1,11 +1,14 @@
+//! Handle rendering of the viewport
 use ::rltk::{Point, Rltk};
 use ::specs::prelude::*;
 
 use crate::map::tile_glyph;
 use crate::{colors, Hidden, Map, Position, Renderable};
 
+/// Whether to render an outline of the current map's boundaries
 const SHOW_BOUNDARIES: bool = false;
 
+/// Get the rectangle representing the current viewport
 pub fn get_screen_bounds(ecs: &World, _ctx: &mut Rltk) -> (i32, i32, i32, i32) {
     let player_pos = ecs.fetch::<Point>();
     // let (x_chars, y_chars) = ctx.get_char_size();
@@ -22,6 +25,7 @@ pub fn get_screen_bounds(ecs: &World, _ctx: &mut Rltk) -> (i32, i32, i32, i32) {
     (min_x, max_x, min_y, max_y)
 }
 
+/// Render the current viewport
 pub fn render_camera(ecs: &World, ctx: &mut Rltk) {
     let map = ecs.fetch::<Map>();
     let (min_x, max_x, min_y, max_y) = get_screen_bounds(ecs, ctx);
diff --git a/src/effects.rs b/src/effects.rs
index 3f4fae0..9c37a06 100644
--- a/src/effects.rs
+++ b/src/effects.rs
@@ -15,9 +15,11 @@ pub use targeting::*;
 use crate::spatial;
 
 lazy_static! {
+    /// The shared queue of effects
     pub static ref EFFECT_QUEUE: Mutex<VecDeque<EffectSpawner>> = Mutex::new(VecDeque::new());
 }
 
+/// The kind of effect to cause
 pub enum EffectType {
     Damage {
         amount: i32,
@@ -51,8 +53,8 @@ pub enum EffectType {
     },
 }
 
+/// Who, or what the effect should affect.
 #[derive(Clone)]
-#[allow(dead_code)]
 pub enum Targets {
     Single { target: Entity },
     TargetList { targets: Vec<Entity> },
@@ -60,12 +62,14 @@ pub enum Targets {
     Tiles { tiles: Vec<i32> },
 }
 
+/// An effect for the queue
 pub struct EffectSpawner {
     pub creator: Option<Entity>,
     pub effect_type: EffectType,
     pub targets: Targets,
 }
 
+/// Adds an effect to the queue
 pub fn add_effect(creator: Option<Entity>, effect_type: EffectType, targets: Targets) {
     EFFECT_QUEUE.lock().unwrap().push_back(EffectSpawner {
         creator,
diff --git a/src/game_log.rs b/src/game_log.rs
index d598d2a..771ebe7 100644
--- a/src/game_log.rs
+++ b/src/game_log.rs
@@ -1,9 +1,12 @@
+/// A struct to hold the player's game log.
 #[derive(Default)]
 pub struct GameLog {
     pub entries: Vec<String>,
 }
 
 impl GameLog {
+    /// Convenience constructor that adds the first
+    /// entry to the game log.
     pub fn new<S: ToString>(first_entry: S) -> Self {
         let mut log = GameLog::default();
         log.append(first_entry);
@@ -11,6 +14,10 @@ impl GameLog {
         log
     }
 
+    /// Convenience method for adding an entry to the game log.
+    /// Generic on the [`ToString`] trait so that [`&str`], [`String`],
+    /// and `&String` types, all work without more type juggling
+    /// at the call site.
     pub fn append<S: ToString>(&mut self, s: S) {
         self.entries.push(s.to_string());
     }
diff --git a/src/main.rs b/src/main.rs
index a5a7da7..e816aa2 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,3 +1,6 @@
+//! Roguelike
+//!
+//! An implementation of a rogue-like dungeon-crawler game.
 #[macro_use]
 extern crate lazy_static;
 
@@ -40,6 +43,21 @@ pub use rect::Rect;
 pub use state::*;
 
 /// Cut down on the amount of syntax to register components
+///
+/// Compare:
+/// ```ignore
+/// let mut game_state = State::new();
+///
+/// register!(state <- ComponentA, ComponentB, ...);
+/// ```
+///
+/// Without macro:
+/// ```ignore
+/// let mut game_state = State::new();
+///
+/// state.ecs.register::<ComponentA>();
+/// state.ecs.register::<ComponentB>();
+/// ```
 macro_rules! register {
     // $state is needed to get the scope at the usage point
     // $Type is the Component type that is being registered
@@ -50,6 +68,14 @@ macro_rules! register {
     }
 }
 
+/// Sets up the game.
+///
+/// * Creates the [`State`] object
+/// * Registers [`components`](register!)
+/// * Loads the dynamic game entities using the [`raws`](crate::raws::load_raws) module
+/// * Generates the map builder environment
+/// * Creates the [`Player`](crate::spawner::player)
+/// * Generates the first [`map`](crate::state::State::generate_world_map)
 fn init_state() -> State {
     let mut state = State::new();
 
@@ -146,6 +172,7 @@ fn init_state() -> State {
     state
 }
 
+/// The entry point
 fn main() -> ::rltk::BError {
     let context = ::rltk::RltkBuilder::simple(80, 60)
         .unwrap()
diff --git a/src/map.rs b/src/map.rs
index 5bd0223..cab399f 100644
--- a/src/map.rs
+++ b/src/map.rs
@@ -1,13 +1,13 @@
+//! An object to hold the state of the current level's map
 mod dungeon;
 mod themes;
 mod tiletype;
 
 use std::collections::HashSet;
 
-use ::rltk::{Algorithm2D, BaseMap, Point, SmallVec};
+use ::rltk::{Algorithm2D, BaseMap, Point, SmallVec, RGB};
 use ::serde::{Deserialize, Serialize};
 pub use dungeon::*;
-use rltk::RGB;
 pub use themes::*;
 pub use tiletype::{tile_opaque, tile_walkable, TileType};
 
@@ -30,6 +30,8 @@ pub struct Map {
 }
 
 impl Map {
+    /// Converts an `(x, y)` coordinate to the flat index within the
+    /// `Map`'s internal array.
     pub fn xy_idx(&self, x: i32, y: i32) -> usize {
         (y as usize * self.width as usize) + x as usize
     }
@@ -83,7 +85,7 @@ impl BaseMap for Map {
     }
 
     fn get_available_exits(&self, idx: usize) -> SmallVec<[(usize, f32); 10]> {
-        let mut exits = rltk::SmallVec::new();
+        let mut exits = SmallVec::new();
         let x = idx as i32 % self.width;
         let y = idx as i32 / self.width;
         let w = self.width as usize;
@@ -125,7 +127,7 @@ impl BaseMap for Map {
         let p1 = Point::new(idx1 % w, idx1 / w);
         let p2 = Point::new(idx2 % w, idx2 / w);
 
-        rltk::DistanceAlg::Pythagoras.distance2d(p1, p2)
+        ::rltk::DistanceAlg::Pythagoras.distance2d(p1, p2)
     }
 }
 
diff --git a/src/map/dungeon.rs b/src/map/dungeon.rs
index a745e13..6e199f7 100644
--- a/src/map/dungeon.rs
+++ b/src/map/dungeon.rs
@@ -1,3 +1,4 @@
+//! Functionality that is common to all the currently generated maps.
 use std::collections::{HashMap, HashSet};
 
 use ::rltk::{Point, RandomNumberGenerator};
diff --git a/src/map/themes.rs b/src/map/themes.rs
index bd2e279..165a194 100644
--- a/src/map/themes.rs
+++ b/src/map/themes.rs
@@ -1,3 +1,4 @@
+//! Different looks for the same set of [`TileType`]s
 use ::rltk::{to_cp437, FontCharType, RGB};
 
 use super::{Map, TileType};
diff --git a/src/map/tiletype.rs b/src/map/tiletype.rs
index 10ce6bb..18f2b32 100644
--- a/src/map/tiletype.rs
+++ b/src/map/tiletype.rs
@@ -1,5 +1,6 @@
 use ::serde::{Deserialize, Serialize};
 
+/// The type of location for a specific square of a [`Map`](crate::map::Map)
 #[derive(PartialEq, Eq, Hash, Copy, Clone, Serialize, Deserialize)]
 pub enum TileType {
     Wall,
@@ -17,6 +18,7 @@ pub enum TileType {
     Stalagmite,
 }
 
+/// Can you go through this type of map tile?
 pub fn tile_walkable(tt: TileType) -> bool {
     matches!(
         tt,
@@ -32,6 +34,7 @@ pub fn tile_walkable(tt: TileType) -> bool {
     )
 }
 
+/// Is it impossible to see through this type of map tile?
 pub fn tile_opaque(tt: TileType) -> bool {
     matches!(
         tt,
@@ -39,6 +42,7 @@ pub fn tile_opaque(tt: TileType) -> bool {
     )
 }
 
+/// How difficult is it to cross this type of map tile?
 pub fn tile_cost(tt: TileType) -> f32 {
     match tt {
         TileType::Road => 0.8,
diff --git a/src/rect.rs b/src/rect.rs
index efe31cb..e101ba1 100644
--- a/src/rect.rs
+++ b/src/rect.rs
@@ -1,3 +1,4 @@
+//! Four points, one plane, 90° angles
 use ::serde::{Deserialize, Serialize};
 
 #[derive(PartialEq, Copy, Clone, Serialize, Deserialize)]
diff --git a/src/state.rs b/src/state.rs
index 1c98f6f..d293302 100644
--- a/src/state.rs
+++ b/src/state.rs
@@ -1,3 +1,4 @@
+//!
 use ::rltk::{GameState, Point, Rltk};
 use ::specs::prelude::*;
 
@@ -21,8 +22,10 @@ use crate::trigger_system::TriggerSystem;
 use crate::visibility_system::VisibilitySystem;
 use crate::{ai, camera, damage_system, effects, saveload_system, spawner};
 
+/// Whether to show a visual representation of map generation
 pub const SHOW_MAPGEN_VISUALIZER: bool = false;
 
+/// The main actions possible with a vendor
 #[derive(PartialEq, Copy, Clone)]
 pub enum VendorMode {
     Buy,
@@ -30,6 +33,7 @@ pub enum VendorMode {
 }
 
 #[derive(PartialEq, Copy, Clone)]
+/// The states for the game engine's state machine
 pub enum RunState {
     AwaitingInput,
     PreRun,
@@ -203,6 +207,7 @@ impl State {
 }
 
 impl GameState for State {
+    /// The big, nasty, state machine handler
     fn tick(&mut self, ctx: &mut Rltk) {
         let mut newrunstate;
         {