Here are the collected backstories of all of the characters that come up in the story, set from the perspective of just before the story starts. I'll update this with every chapter I release. Warning: May contain spoilers!
Hiker
Faction: Loner
Armour: SEVA Suit
Signature Weapon: Custom Silenced AK74
Skills: Skilled Pathfinder
Hiker has been a stalker for longer than most, and has experienced much of the Zone's history first hand. A skilled trekker and pathfinder, he is often found in the wilderness areas of the Zone, trying to reach areas previously undiscovered. Not much of a fighter, he prefers stealth and tactics over pure force.
Garry
Faction: Loner
Armour: Sunrise Suit
Signature Weapon: VSS Vintorez
Skills: Master Guide and Pathfinder
Garry is a well-known character among stalkers, renowned for discovering routes to Yanov Station and the Jupiter Factory, Eastern Pripyat and other locations in the central Zone, and also one of Barkeep's staff for a time. He is without peer at his trade, and also a skilled artifact hunter. Like many guides, he often avoids combat, and spends much of his time leading people from place to place. A pragmatic man, his past is enigmatic, and there are many rumours that state that he is Guide, the man thought to be first stalker into the Zone and affiliated with Strelok's group.
Forester
Faction: None
Armour: None
Signature Weapon: Custom VSS (Given to Scar)
Skills: Groundsman for the Red Forest before the incident
Forester was the caretaker for the Red Forest before the accident in 1986, and now still lives there, keeping his vigil over the forest, helping those in it's deadly clutches to survive. He was instrumental in helping Clear Sky and Scar reach Limansk, and freeing the party of Mercenaries headed by Leshiy.
Giant
Faction: Monolith (Abandoned0
Armour: Monolith Exoskeleton
Signature Weapon: AS VAL, PKM
Skills: None outstanding
One of the few ex-Monolithians, he is a giant in stature, bearing many pieces of extremely rare kit, such as his PKM and exoskeleton. Though bearing little to no knowledge of his life before waking up outside of Monolith control, he was obviously one of their heavy-weapons experts, and his time in the Monolith has left him privy to many secrets of the Zone.
Murk
Faction: Freedom
Armour: Custom SEVA Suit
Signature Weapon: FN F2000
Skills: Decent survivalist
Murk is a little-known expert among Freedom's ranks, spending almost all of his time away from his faction, scouting the depths of the Zone. Unlike most stalkers, Murk lives most of his life away any safe stalker camp, sleeping rough and used to scavenging for gear and supplies. After hooking up with fellow Freedom veterans Leshiy and Yar, they began to delve deeper into the center of the Zone, leaving behind the outdated and declining faction war between Duty and Freedom.
Hog
Faction: Ex-mercenary
Armour: Grey Exoskeleton
Signature Weapon: Sig 550
Skills: Long time veteran of the Zone
Hog was one of the best Merc commanders; level-headed and disciplined. After completing his mission in the Army Warehouses, and securing the release of Leshiy from a space anomaly, he remained in the Zone to repay his debt to Kostyan, a freedom expert who saved his life. The disappearance of his close friend Hatchet and his squad initially led him to the Northern Zone.
Max
Faction: Freedom
Armour: Guardian of Freedom Suit
Signature Weapon: Custom SVU; Gauss rifle
Skills: Master Sniper, Freedom Second in Command
Max is a reclusive character, Lukash's right hand man and chief scout after the emission storms wracked the Zone. Ruthless and focused, he is one of the few that has the skills necessary to live on his own almost without need of the main stalker safe zones.
Yar
Faction: Freedom
Armour: Guardian of Freedom Suit
Signature Weapon: personally tuned SVD;
Skills: Technician, skilled sniper, renowned expert in tuning sniper rifles
One of the oldest of the real stalkers in the Zone, who spent time hiking through the wilderness before coming there. He's the undisputed master of tuning all kinds of weapons for marksman purposes in the Zone, and one of Freedom's crack snipers.
Alexander Degtayrev
Faction: Ukrainian Secret Service
Armour: Various
Signature Weapon: Various
Skills: Ex Military Stalker, excellent bargainer and leader
The USS agent responsible for infiltrating the Zone to discover the source of the Fairway disaster, he gained much repute by successfully leading the first team from the Northern Zone into the barely touched residential east side of Pripyat.
Strelok
A legend among stalkers, a survivor of the full malice of the Zone and a man bearing the distinctive S.T.A.L.K.E.R tattoo that gave him his nickname 'The Marked One'.