u/Turbulent_Okra7518

Gordon Freeman:

Gordon Freeman shows early-career motivation to use science for civilian benefit and has personal attachments (e.g., family photo), suggesting empathy and humanity.
After the Black Mesa Resonance Cascade, he immediately works to repair the damage, assisting scientists and security forces while fighting through Xen and HECU threats.
He helps evacuate and protect multiple scientists and civilians, consistently prioritizing survival and resistance success over personal safety.
In HL1, he aids key efforts like launching a satellite attempt to mitigate the disaster and ultimately defeats the Nihilanth to help seal the Xen breach.
In HL2, he joins the resistance to rescue Eli Vance, supports uprisings against the Combine, and plays a major role in destabilizing their control of City 17.
In the two episodes of Half-Life 2, he assists major evacuations, defends resistance strongholds like White Forest, and helps secure the final steps toward closing the Combine portal connection.

Adrian Shephard:

Adrian Shephard (himself an HECU Marine) frequently spares Black Mesa scientists and security personnel despite standing orders and widespread Marine hostility toward them.
After learning the truth behind his mission, he continues protecting survivors, seemingly influenced by gratitude toward those who saved his life.
He shows no hostility toward Gordon Freeman and even allows him passage toward Xen after recognizing larger threats like Race X and Black Ops forces.
He repeatedly risks himself to rescue fellow Marines, which demonstrates loyalty to his fellow soldiers despite the chaos of the incident.
Actively fights against Black Ops operatives attempting to eliminate both HECU survivors and Black Mesa personnel, pushing them back during the later stages of the Black Mesa incident.
He also combats the Race X invasion, disarms a nuclear device meant to destroy Black Mesa, and ultimately kills the Gene Worm to end their invasion.

Barney Calhoun:

Security Guard who engages in combat against HECU Soldiers and Xen Aliens primarily to protect himself or protect other guards/scientists
Compared to Gordon and Adrian, he operates with far less advantages, relying on scavenged weapons and limited equipment instead of advanced suits like the HEV or PCV or outside assistance.
In Blue Shift, he rescues scientists (including Dr. Rosenberg), assists in setting up escape teleportation technology, and risks his life securing power sources under heavy enemy presence.
He ultimately holds critical positions during the Black Mesa incident, staying behind to activate and stabilize the teleporter so his group can escape safely.
In HL2, he works undercover inside Civil Protection, gathering intelligence, sabotaging Combine operations, and helping protect resistance infrastructure like Kleiner’s lab.
During the uprising and evacuation phases, he becomes a resistance field leader, helping coordinate assaults on key Combine targets and personally assisting civilian escapes during the Citadel collapse.