Spawning Enemies

Tutorial 9: Spawning Enemies

First, what does spawning mean? Spawning refers to a method in game design where your enemies automatically get created

You will want to make your enemies appear at random in a top-down or side-scrolling shooter game, so that they do not become predictable every time the game is played.

Placing hundreds of enemies in a room will not work. Instead, you want enemies to randomly generate themselves. For this, you will need to make use of alarm events.

Create an enemy spawner object

1. 1. Create an object called objEnemySpawner – this object will have no associated sprite
   2. Add a Create event, inside the event type this code:

      maxEnemies = 10; // variable to limit the amount of enemies in the room at once
      
      spawnRateLow = 20;
      
      spawnRateHigh = 80;
      
      alarm[0]=120; //trigger alarm 0 for the first time 2 seconds into the game
      
      //set this to give your player a chance before enemies appear
      

   3. Create an Alarm 0 event on the spawner object with this code:

      
      
      if(instance_number(objEnemy1) < maxEnemies){
      
      instance_create_layer(irandom_range(32,928), irandom_range(32,298), layer, objEnemy1); 
      
      //spawn your enemy at a random point on the x-axis, between 32 &928 
      // random point on the y-axis between 32 and 298
      //change these values to match the size of your enemy sprite
      
      }
      
      alarm[0] = irandom_range(spawnRateLow, spawnRateHigh);
      
      //alarm will now re-trigger between a the low and high values set in the Create event
      
      

   4. Drag the objEnemySpawner object into the room