How to reduce the chance of an enemy spawning?

Questions & Answers
1

So far I’ve got the code for 3 spawn points and 2 enemies. The code will select one spawn at random, then it will select one of the 2 enemies to spawn at the selected spawn point.

One of the enemies is like a mini-boss, so a reduced spawn rate would be helpful.

Ps. All of this is in C# before you go ahead and look at the code (I know some people like to work in other coding languages)

public GameObject[] Enemy;
	public Transform[] EnemySpawn;
	private float ReSpawnTimer;
	public float ReSpawnRate;
	
	
	void Start ()
	{
		ReSpawnRate = 300;
		int spawnPointIndex = Random.Range (0, EnemySpawn.Length);
		Instantiate (Enemy[Random.Range(0,Enemy.Length)], EnemySpawn [spawnPointIndex].position, EnemySpawn [spawnPointIndex].rotation);
	}
	
	void Update () 
	{
		ReSpawnTimer = ReSpawnTimer + 1;
		if (ReSpawnTimer >= ReSpawnRate) 
		{
			ReSpawnTimer = 0;
			Spawn ();
		}
	}
	
	void Spawn ()
	{
		int spawnPointIndex = Random.Range (0, EnemySpawn.Length);
		Instantiate (Enemy[Random.Range(0,Enemy.Length)] , EnemySpawn [spawnPointIndex].position, EnemySpawn [spawnPointIndex].rotation);
	}

Any help in this would be greatly appreciated. And thanks, in advance.

2

Could you not just check for a random percentage?

int spawnChance = Random.Range (0, 101); //Returns a number between 0 and 100.

Then check if the spawnChance is within your desired percentage, like so:

int bossSpawnPercentage = 80;
...
if (spawnChance >= bossSpawnPercentage)
...

Essentially there is a 20% chance of spawning a boss.

Understand? You should be able to implement this into your code with a little tweaking.