Paul Tozour

4,111pages on
this wiki
Add New Page
Add New Page Talk1
This article is written
from the Real Life
point of view
Paul Tozour

Paul Tozour created the AI for several bosses in the latter two Metroid Prime Trilogy games. These bosses were the Chykka Larva, Dark Samus in Metroid Prime 2: Echoes and Metroid Prime 3: Corruption, the Defense Drone, the Grapple Guardian, Helios, Korakk and "Beast Rider", Meta Ridley in his Corruption appearance and Rundas. [1][2][3][4]
He no longer works in the game industry.


July 2003-June 2008. Senior Engineer, Retro Studios / Nintendo. Extensive gameplay, AI, and tools development for Metroid Prime 2: Echoes, Metroid Prime 3: Corruption, and two subsequent unannounced products. Responsibilities included custom AI development and tuning of dozens of creature AI systems and boss encounters. Designed and built an extensive real-time artificial intelligence (AI) diagnostic and debugging toolset, a collision abstraction system and attachment management system, and refactored pathfinding systems for flying and jump-capable creatures. Rewrote the internal in-game debugging system to be fully hierarchical and make full use of the Wii remote pointer. Mentored several engineers involved in AI development.


Dark Samus (Metroid Prime 3)

This is the final battle in the final Metroid Prime title, Metroid Prime 3: Corruption. Dark Samus clones itself repeatedly in this battle and works together with its clones (or "echoes") in many interesting ways. In a lot of ways, this encounter represents a culmination of many things I had been working toward since the original Dark Samus battle in Metroid Prime 2.


I'm very proud of the work I did on Helios for Metroid Prime 3: Corruption; it's easily my favorite boss character (though this video really doesn't do it justice as the individual bots are almost invisible at this resolution). It was also a great opportunity to further develop my design skills, as I proposed the boss encounter and did all of the prototyping and the majority of the design work in addition to the engineering.

I wanted Helios to defy easy understanding by continually morphing and changing in ways that deny the player any easy categorization of its identity.

During various parts of the encounter, Helios freely transitions between a loosely-coordinated group of separate flying robots, a set of separate clusters that have tight coordination among themselves, or single highly coordinated creature that acts more like a single entity than a swarm. The swarm becomes a sphere, a tornado, a massive ring, a set of smaller rings, a giant humanoid creature, a loose flock of creatures swirling around the main Prime Bot who controls the swarm, or the Prime Bot acting all alone ... continually and gradually transforming between its many different stages and doing everything it can to defy any simple definition the player might try to put it into.

If you look closely, you'll notice that the swarm doesn't change state all at once; in most cases, the bots smoothly and gradually transition between the various forms, underscoring the idea that the intelligence is shared among multiple levels of the hierarchy (the swarm as a whole, the individual forms, and the bots themselves).

Dark Samus (Metroid Prime 2: Echoes)

The work I did on Dark Samus on Metroid Prime 2: Echoes was my attempt to introduce a faster and more nimble type of AI opponent to the Metroid Prime series. We weren't trying to replicate a "deathmatch" against an AI, but we wanted to bring something really new to the table -- an enemy that wasn't necessarily a massive boss creature, but which could challenge the player with its speed, its agility, and its tactics.

This type of AI proved successful and served as a general model for many creatures in the sequel, including Rundas, Gandrayda, and the new Dark Samus. Although there are 3 separate Dark Samus battles in Metroid Prime 2: Echoes, I've included the second Dark Samus battle here since it really builds on the features that worked in the first encounter very nicely.


Rundas is one of the three bounty hunters from Metroid Prime 3: Corruption, and he builds on the nimble, Dark Samus style of AI

Meta Ridley

This boss encounter was originally intended to be the first boss the player encounters in Metroid Prime 3: Corruption. Since this was the first Metroid Prime game on the Wii, we set out with the goal of orienting this encounter more toward a point-and-shoot arcade style of gameplay to get players comfortable with using the Wii remote before asking them to use it in conjunction with the analog stuck. As such, the player spends the battle falling down the tube either above Meta Ridley, below Meta Ridley, or in his hand, and the battle is oriented mostly toward pure arcade action.

Defense Drone

This is an encounter against a mechanoid guardian creature on SkyTown that was designed to make use of Metroid Prime 3's grapple beam feature.

Korakk and Beast Rider

This is an encounter on planet Bryyo that was designed to make use of several different player abilities in Metroid Prime 3, including the grapple beam, morphball mode, and Hyper Mode.


  • "In this interview, Paul Tozour discusses his work on the AI of Metroid Prime 3, most notably the boss called Helios. He discusses the swarms in the game as the inspiration for Helios, and the various stages of the prototype. Paul also discusses the various levels of intelligence that goes into this multi-agent system, including the various forms of Helios: creature, shapes, swarm, multiple swarms, and particles system. You'll also learn about the various obstacles encountered, such as performance in collision or avoidance, and how they were resolved in practice."

Also on Fandom

Random Wiki