So while playing Half-Life I encoutered two parts where some Vortigaunt(s) did not attack. This was due to a bug, I’m sure, but it gave a false sense of freedom that I really liked. The ability to spare certian hostiles (depending on context) is a wonderful ability in games.
This ability is great and is fun to do when I’m killing a ton of enemies and I start to wonder why they keep trying to kill me. So I disarm one and leave him amongst an area I won’t be returning to, as a sign of peace.
Let me describe how it happened in Half-Life (goldrc): I was in the hallway right before the lift to the first encounter of those Black Spec-Ops Ninjas. I get to the part where I’m being ambushed by two Vortigaunts spawning on both ends of the hallway. I kill the one back where I came, get into cover, shoot the one down the hallway, get into cover, and reload. I pause, knowing it’s not dead. I go around the corner aiming for the head but I pause again as it hasn’t attacked. No more Vortigaunts are appearing and I decide to go up the lift. The Vortigaunt folows me up the lift and still does not attack. The security guard dies and I decide to sent the Vortigaunt back down the elevator, thus sparing it.
The other instance was much later in the game, durring Xen. There comes a part where you walk into an open-ish area that contains something that somewhat resembles a ski lift. I crouch walk into the area and a Vortigaunt walks right next to me but doesn’t react. I soon discover that as long as I don’t bump into these Vortigaunts they will not do their usual attack routine. I can go about my buisness and watch them make hand gestures as some run around the place.
Both of these experiences greatly added to the feel of the game and both make sense when Half-Life 2 is factored in. These were great parts and were enjoyable.
This sort of thing has been built into other games too! Take Halo 3 for example. On the level Crow’s Nest there is a scene with Thel 'Vadam where he attacks two hostile Drones and yells to them about how their leader (the “prophet” Truth) is lying to them (which he is). Normaly Thel 'Vadam kills the drones, but if the player interferes and stops him from killing the drones it will cause certian drones throughout the level to be friendly.
(I also recall a part in Dues Ex where if you spare some certian random people it causes a truce or something.)
What I’m trying to get across is that this is a great feature that should be possible somewhere in the game. Now I’m not suggesting that more than a handful of NPC’s be capable of this, but when a certian NPC encounters a certian pre-set situation it could cease attacking. The ability to spare the life of someone, wether to be a lone survivor or as a sign of peace, is a great thing to be able to do in a videogame.
(The Marines or non-sentient Xen wildlife should not be considered for this.)