Family-friendly PC/PlayStation 3 MMO Free Realms has notched up 20 million registered users since its launch in 2009, according to publisher Sony Online Entertainment.
To celebrate, every player gets an in-game varsity letterman jacket for their character, providing you log-in at least once between 21st and 31st October 2011.
"This benchmark is an honor and a true testament of SOE's success with Free-to-Play games," commented SOE boss John Smedley.
"Free Realms delivers a truly captivating, quality gameplay experience that keeps our community engaged and continues to attract new players every day."
In other Free Realms news, SOE has also announced it's holding a special in-game Halloween event between 24th October and 7th November, featuring various horror-themed mini-games and special items to pick up.