Hypergaming Network's Stalker RP server takes place in the Shadow of Chernobyl timeline, just before Strelok makes all of his breakthroughs. You play as a stalker in the zone.Whoever that is will be your decision, perhaps a bandit, or a loner leading a group to what you think will end in riches.
In this picture you can see the scale of how many players there are. Top right shows red blips which are infact other players. This was a tunnel event in which groups of stalkers would go out into these tunnels in search of items and loot. While being attacked by various mutants, dangerous anomalies and zombies. It was truely a great event.