The co-founder of Australian studio League of Geeks, Adam Duncan, has died.

The developer revealed the news on Twitter, saying that it was "saddened" to announce his passing. There's no indication what the cause of death was.

"Adam was a founding member of League of Geeks, respected art director, concept artist and animator," the studio wrote.

"His stunning illustrations and character designs gave our projects a unique and joyful spirit, packed with heart.

"His wonderful sense of humour and gentle humility flowed throughout all his work, into our games, and into the hearts and minds of millions of players. Adam dedicated himself to his beloved craft and we consider ourselves so incredibly lucky and forever grateful that he transported us all to those beautiful worlds he dreamed."

Some of his colleagues also took to Twitter to pay their respects to their departed friend. 

"Adam was my friend & creative collaborator in life - it feels incredibly lonely to be in a world where we can't share in the crazy things we both loved & worked on," League of Geeks creative director – and fellow co-founder – Ty Carey said. 

"Despite his massive talent, he was a gentle, evolved human who naturally only considered the people around him."

Meanwhile, co-founder and studio director Trent Kusters added: "There aren’t many people you could envision working alongside every day for the rest of your life. Adam was one of them. A gentle giant, in stature, temperament and talent. What I would give for one more project, one more dinner, one more chat.

"Love you, buddy."