A fan campaign designed to encourage more Half-Life information from developer Valve plans a mass gameplay session this Saturday.

Steam group A Call for Communication (Half-Life), which boasts more than than 29,500 members, has organised a huge Half-Life 2 play session this weekend, designed to raise awareness of its campaign by boosting the game up Steam's most-played list.

The fan collective aims to encourage information from Valve on when the Half-Life series might return, be that in the form of Half-Life 2: Episode 3 or a fully-fledged Half-Life 3.

Group numbers have swelled from 10,000 members since the campaign first hit the headlines two weeks ago.

A Call for Communication's Half-Life 2 play session begins at 7pm UK time this Saturday night.

"Instead of focusing efforts in a negative and disrespectful way, we have decided to gain Valve's attention by delivering a basic message: 'Your oldest and longest running fanbase would like better communication,'" the Steam group's description reads.

"Hopefully such attention will be recognized by Valve, and the community's voice will be heard."