FarmVille, once the most popular game on Facebook, is to close down in December, more than 11 years after its launch.
At its peak, FarmVille had more than 80 million players tending to crops and raising animals – and asking Facebook friends for help.
But the social network will stop supporting Flash-based games in December, rendering it unplayable.
Maker Zynga encouraged players to spend any remaining credits before then.
In-app purchases will be available until 17 November, after which the game’s payment system will be turned off.
Zynga is planning a number of in-game activities to allow fans to give the game a send-off.
Its other farming games, including FarmVille 2 and Tropic Escape, are available on mobile and will not be affected.
FarmVille 3 is also due for release on mobile soon.
Zynga thanked its fans for “an incredible 11 years” – and explained the demise of Adobe Flash Player was behind the decision.
“As previously stated, Adobe will stop distributing and updating Flash Player for all web browsers and Facebook will stop supporting Flash games on the platform completely after December 31 2020,” it said.
“FarmVille will therefore be directly affected as a result of this.
“We are aware that many of you have been with us since the very beginning, helping to build an incredible global community of players over the years who’ve enjoyed this game just as much as we have.
“For that, we say thank you.”
Ampere Analysis games research director Piers Harding-Rolls said: “The game was synonymous with the explosion in social-network gaming in the late 2000s, primarily on Facebook.
“But that market was heavily disrupted by the mass adoption of smartphones and related app stores.
“And the social-network gaming market on PC shrunk significantly.
“The broader internet industry’s decision to turn a corner on Flash by the end of 2020 and the closure of FarmVille will not have a significant impact on Zynga’s bottom line.”
Adobe Systems announced in 2017 it planned to phase out its Flash Player plug-in this year.
The technology was once one of the most widely used ways to watch video clips and play games.
But flaws in its code meant it became a popular way for hackers to infect computers.
And much of its functionality has been replaced by HTML5 technology.