30: Rogue Part 3: Finishing Touches

WARNING This exercise is in DRAFT status, so there may be errors. If you find any, please email me at help@learncodethehardway.com so I can fix them.

The final exercise in this module should be the simplest one. You are only going to add basic combat to the game. Combat in games like this is generally based on "player moves into square where monster is." You'll get a basic form of this working, then I'll give you some extra things you can do to push this further so you can make your own game.

data.go Changes

Let's turn off SHOW_PATHS now that pathing is working:

View Source file curse-you-go-rogue/04_combat/data.go.diff Only

--- 03_pathing_enemies/data.go  2025-10-06 02:44:43.658927000 -0400
+++ 04_combat/data.go   2025-10-05 23:24:48.595383100 -0400
@@ -11,5 +11,5 @@
   RENDER = true
   SHOW_RENDER = false
-  SHOW_PATHS = true
+  SHOW_PATHS = false
   HEARING_DISTANCE = 6
 )

movement.go Changes

To make combat work you only need to detect that the player is trying to move into an Occupied() cell and then Attack():

View Source file curse-you-go-rogue/04_combat/movement.go.diff Only

--- 03_pathing_enemies/movement.go  2025-10-06 12:00:47.091211600 -0400
+++ 04_combat/movement.go   2025-10-06 12:00:49.969794700 -0400
@@ -7,5 +7,7 @@
   }
 
-  if !game.Occupied(target) {
+  if game.Occupied(target) {
+    game.Attack(target)
+  } else {
     game.Player.Pos = target
   }

This is only a first step, and the combat can get very complex from here if you want, but this is mostly what you do.

New main.go

It's easier to give you a new main.go then to use a .diff. The algorithm seems to really hate the changes to this file.

View Source file curse-you-go-rogue/04_combat/main.go Only

package main

func main() {
  DebugInit()

  game := NewGame(17, 11)
  game.InitScreen()

  for {
    game.NewMap()
    dead_ends := game.NewMaze()
    game.PlaceEnemies(dead_ends)
    game.Render()

    for game.HandleEvents() && game.Player.HP > 0 {
      game.EnemyDeath()
      game.CalculatePaths()
      game.EnemyPathing()
      game.Render()
    }

    if game.Player.HP <= 0 {
      game.Restart()
    } else {
      game.Exit()
    }
  }
}

New combat.go

There's now a new combat.go file that has the combat system:

View Source file curse-you-go-rogue/04_combat/combat.go Only

package main

import (
  "fmt"
  "math/rand"
)

func (game *Game) EnemyDeath() {
  is_dead := make([]Position, 0, len(game.Enemies))

  for pos, enemy := range game.Enemies {
    if enemy.HP < 0 {
      is_dead = append(is_dead, pos)
    }
  }

  for _, pos := range is_dead {
    delete(game.Enemies, pos)
  }
}

func (game *Game) ApplyDamage(attacker *Enemy, defender *Enemy) {
  damage := rand.Int() % attacker.Damage
  defender.HP -= damage
  if damage == 0 {
    game.SetStatus("MISSED!")
  } else if defender.HP > 0 {
    game.SetStatus(fmt.Sprintf("HIT %d damage", damage))
  } else {
    game.SetStatus("DEAD!")
  }
}

func (game *Game) Attack(target Position) {
  enemy, hit_enemy := game.Enemies[target]

  if hit_enemy {
    game.ApplyDamage(&game.Player, enemy)
    game.ApplyDamage(enemy, &game.Player)
  }
}

The combat system consists of three functions:

• EnemyDeath() -- This is run once every turn and simply goes through the map of game.Enemies and checks if any have HP below zero. If they do then it removes them. This would be where you can put loot drops.
• ApplyDamage() -- This does the damage calculations if Attack() determines the player or an enemy gets hit.
• Attack() -- This is called and it use the game.Enemies map to determine if an enemy is in that position, and if it is then it calls ApplyDamage() on both the enemy and the player.

Going Farther

You have now reached the end of Module 2, but you aren't done yet. You should spend some time pushing this game as far as you can. Here's some suggestions you can implement:

• Add rooms to the map generation. You can do this by running NewMaze() twice. First you run NewMaze() and get a list of dead_ends. Randomly select some of the dead_ends. Reset the map back to all # (WALL) and then "cut" rooms at the randomly selected dead_ends. Once you have holes cut out where the rooms go you can re-run NewMaze() and the hunt-and-kill algorithm will walk around them producing a working maze with the rooms.
• Play with the size and positioning of these rooms. You may notice an interaction when the room is odd sized (3, 5, 7) or placed on an odd coordinate (3,5).
• Combat could definitely be improved.
• Make the map bigger.
• Create a "fog of war" system. This is easily done by having another grid of bool that only records where the player has been. Then change your DrawMap() to only draw the cells that have a true in the fog map.
• Better UI under the map.
• Loot! Right now you have no concept of weapons, loot, gold, or healing items.
• Healing. Can't really have a Rogue without healing.

Try to get those to work, and then see what you can do from there. Can you make the code better than mine?