The Riot designer behind TFT, Nexus Blitz and Odyssey is leaving to make his own game

Naerlyn Published July 13, 2026

Stephen “Mortdog” Mortimer is leaving Riot Games to continue his career elsewhere. Beyond being the face of Teamfight Tactics, Mortdog was also behind some of League of Legends’ well-loved game modes. After a tenure of almost ten years, he leaves to make his own game.

Mortdog leaves Riot Games

Mortdog’s early career included an 11-year stint with Nintendo, following which he became a Gameplay Designer, then Senior Game Design Director at Riot Games. Working on League of Legends from 2016 to 2019, he contributed to several memorable game modes, namely:

• The Butcher’s Bridge Bilgewater map for ARAM
• The 2018 PvE game mode Odyssey: Extraction
• The 5v5 game mode Nexus Blitz
• The All Random URF variant.

To this day, Odyssey is quoted as the most missed PvE game mode, despite its LoL playtime not lining up back then. Nexus Blitz was iterated upon and brought back several times, and URF was the first major hit for a League game mode. As for the Butcher’s Bridge, it has now become a permanent addition.

Mortdog has also worked on out-of-game League systems. Notably, he’s contributed to the changes to blue essence, summoner experience, missions, loot, and the tutorial.

The face of Teamfight Tactics

Mortdog leaves Riot Games after spending seven years as the TFT Lead Gameplay Designer. Image credit: Colin Young-Wolff / Riot Games

After working on League of Legends, Mortdog became the Lead Gameplay Designer for Teamfight Tactics. Stephen took this role at the very beginning of the game and kept it ever since until now.

On April 17, the designer announced taking a 12-week sabbatical to step away from Teamfight Tactics. During that time, he started making his own indie game and came out of his break announcing that he was leaving Riot Games and pursuing this project.

“My time at Riot and on TFT as a Game Designer has come to an end. Just under 10 years, and to be honest I thought it was going to be longer, but sometimes things change.” – Mortdog

On top of being a designer, Mortdog also handled the balance of the game. Mostly though, he was the person the entire community associated with TFT.

As such, he would stream the game regularly, cast tournaments, and always be the person people turned to to voice their questions or more frequent complaints.

The community ended up dubbing “having bad luck in TFT” as “getting Mortdog’d”, joking about his ability to personally influence everyone’s rolls.

Featured image credit: Riot Games