Here’s how the game manages the AI in the Doofenshmirtz boss battle at the end of World 1. This guide should not be used as a strategy guide for the boss, but should instead help you get a better understanding of how the AI here works.

During the fight, the game will pick a random number from 0 to 99 inclusive. However, this random number that generates is already predetermined when you start this Perry section, and doesn’t depend on when or how you enter the boss fight.

When you are standing next to Doofenshmirtz: • If the aforementioned random number is less than 25: Doofenshmirtz will maniacally laugh and throw his gnomes at you. • Otherwise, if the last digit is less than 4: Doofenshmirtz will throw his gnomes at you without laughing first. • If it is any other number: Doofenshmirtz will attack you with his bratwurst.

When you are not standing next to Doofenshmirtz: • If the aforementioned random number is less than 25: Doofenshmirtz will maniacally laugh, run in the opposite direction as you for a bit, and throw his gnomes at you. • Otherwise, if the last digit is less than 4: Doofenshmirtz will run away from you and throw his gnomes without laughing first. • If it is any other number: Doofenshmirtz will walk forward for a few seconds attack you with his bratwurst if near. If he doesn’t reach you, he may repeat this again depending on what new number is chosen.

Percentages for when you are standing next to Doofenshmirtz 25%: Doof laughs and throws gnome(s). 28%: Doof will throw gnome(s) without laughing first. 47%: Doof will attack with bratwurst.

Percentages for when you are not standing next to Doofenshmirtz 25%: Doof laughs, runs away and throws gnome(s). 28%: Doof will run away and throw gnome(s) without laughing first. 47%: Doof will walk forward and attack with bratwurst if near.

All research credit for this goes to Mathy.