[1.8.9] Custom Mob Drops With Chance To Drop?

[Monstrous_Apple]

Okay I now have this code:

 

//Zombie Soul
@SubscribeEvent
public void addEntityDrop24(LivingDropsEvent event) {
	if (event.entity instanceof EntityZombie) {
		if (event.source != null && event.source.getEntity() instanceof EntityPlayer) {
			EntityPlayer player = ((EntityPlayer) event.source.getEntity());
			if (player != null) {
				ItemStack holding =  player.inventory.getStackInSlot(player.inventory.currentItem);
				if (holding != null && holding.getItem() instanceof MASoulHarvester) {
					ItemStack itemstack = new ItemStack(MASouls.ZombieSoul, 1);
					event.drops.add(new EntityItem(event.entity.worldObj, event.entity.posX, event.entity.posY, event.entity.posZ, itemstack));
				}
			}
		}
	}
}

 

What this does is makes it so when a player kills a zombie using a specific tool it will drop a soul. How would I make this soul drop have a chance to drop? Like for example a 10% chance to drop a zombie soul when using the specific tool?

 

 

P.S. Massive thanks to Ernio for helping me with this current code.

[Monstrous_Apple]

Okay I now have this code:

 

//Zombie Soul
@SubscribeEvent
public void addEntityDrop24(LivingDropsEvent event) {
	if (event.entity instanceof EntityZombie) {
		if (event.source != null && event.source.getEntity() instanceof EntityPlayer) {
			EntityPlayer player = ((EntityPlayer) event.source.getEntity());
			if (player != null) {
				ItemStack holding =  player.inventory.getStackInSlot(player.inventory.currentItem);
				if (holding != null && holding.getItem() instanceof MASoulHarvester) {
					ItemStack itemstack = new ItemStack(MASouls.ZombieSoul, 1);
					event.drops.add(new EntityItem(event.entity.worldObj, event.entity.posX, event.entity.posY, event.entity.posZ, itemstack));
				}
			}
		}
	}
}

 

What this does is makes it so when a player kills a zombie using a specific tool it will drop a soul. How would I make this soul drop have a chance to drop? Like for example a 10% chance to drop a zombie soul when using the specific tool?

 

 

P.S. Massive thanks to Ernio for helping me with this current code.

[Draco18s]

This is stupid easy.

 

1) Pick any point in there where it's clear that the player has used the right tool and has slain the right creature, but before the drop is added

2) Get a random number

3) If(rand < threshold) { //add drop }

[Draco18s]

This is stupid easy.

 

1) Pick any point in there where it's clear that the player has used the right tool and has slain the right creature, but before the drop is added

2) Get a random number

3) If(rand < threshold) { //add drop }

[Monstrous_Apple]

Sorry but saying "If(rand < threshold) { //add drop }" to me don't help can I have an example or something using the code I currently showed, please?

[Monstrous_Apple]

Sorry but saying "If(rand < threshold) { //add drop }" to me don't help can I have an example or something using the code I currently showed, please?