Workshop › Tower Defense › Step 25 of 42

Lives

What we are doing

Now the enemies are a threat: every enemy that walks off the end of the road costs one of your 20 lives. Its hp drops to 0 so no bullet keeps chasing it, and it pays no gold.

```js
let lives

  lives = 20

  // Walked off the end of the road: it got through. Its hp drops to 0 so no bullet chases it any more.
  for (const e of enemies) {
    if (pointAt(e.d) === null) {
      e.hp = 0
      lives -= 1
    }
  }

  ctx.fillText('Gold ' + gold + '  Lives ' + lives, 10, 26)
```

What it means

• Each enemy past the end takes one life.
• The comment explains why its hp becomes 0.
• The top line joins four pieces; ' Lives ' starts with two spaces.

Your turn

1. Under let gold write let lives; in reset, under gold = 120, write lives = 20.
2. In update, write the comment above the end-of-road loop and lives -= 1 under e.hp = 0.
3. In draw, add the lives to the top line.

Skills: Game states

← Gold for every kill Health bars →

All steps

1. Measure the map
2. A map of tiles
3. Draw it every frame
4. The road as corners
5. Fill in the road
6. Draw the road
7. Walking by distance
8. Enemies on the road
9. Walk
10. Off the end of the road
11. Here they come
12. Towers
13. From a click to a tile
14. Click to build
15. Where can you build?
16. Show the gold
17. Show before you click
18. Show the range
19. Pick a target
20. Fire!
21. A hit hurts
22. Homing bullets
23. Fizzle out
24. Gold for every kill
25. Lives
26. Health bars
27. Build, then defend
28. Space starts a wave
29. The wave is over
30. Stronger every wave
31. Closer together
32. Out of lives
33. No building after the end
34. The most waves survived
35. The game over screen
36. Play again
37. The bottom bar
38. Click to start
39. A second tower: the cannon
40. Tower buttons
41. Splash damage
42. Build it yourself: sell a tower