It used the All Flesh Must Be Eaten ruleset but it could just as easily have used Savage Worlds or indeed d20 Modern (remember that?). I chose All Flesh simply because it was relatively new to me at the time and it felt right given the scenario plot.
Researchers on a scientific base in Antarctica are doing some deep drilling to investigate the mysteries of the Earth. Y'know the usual stuff. They find something unexplained in one of their core samples and during the winter shutdown/lockdown of the site the scientists begin their analysis.
Over a period of weeks the skeleton team on the base start to experience some changes, not least of which involves a greater than normal level of isolationism amongst those on the base.
During the winter shutdown there are no communications from the base due to the storms and once these clear the bases misses it's check-in with the outside world and doesn't respond to messages.
The party consist of a number of scientists (2 or 3) and search & rescue specialists (3 or 4) each of whom have different motivations.
Their official mission is to go in and discover what's wrong at the base and to report back.
On arrival at the base they find diseased corpses and are attacked by (yep you guessed it) Zombies.
Ok so that's a fairly simplistic and very "X-Files" episode like, indeed I'm sure that some of it was inspired by The X-Files but this is where the Character Motivations comes in.
I developed 8 different motivations which would be allocated randomly to the player characters and were to be kept secret at all times. This became the core purpose of the character for the scenario and gave everyone an agenda. These 4 example motivations were designed to build conflict and suspicion amongst the group of characters.
Motivation 1 - A member of a CIA organisation named Project Rebirth which carries out research into genetics and re-animation. On realisation that zombies are present the character will make all attempts to smuggle a core sample out with him and if possible a sample of a zombie…
Motivation 2 - An employee of Parks Engineering’s Geophysical Research division. Has been sent to retrieve 2 core samples but destroy all other core samples. Has spent the past 6 years of his life working in the Arctic, Siberia and Antarctic regions moving from one assignment to another.
Motivation 3 - A member of a cult/religious group named "Purity". Is aware of the find and was dispatched to destroy all of the core samples to ensure that nothing impure gets out. Will want to destroy the zombies as soon as they see them and all evidence of them. Never been to Antarctica.
Motivation 4 - Sent by the USA Homeland Security to 'clean up' the area, destroying all evidence and then to create an accident to ensure that no-one leaves alive. Has never been to Antarctica.
The first time I ran the scenario it was a Total Party Kill (TPK) due to one of the characters causing an explosion which wiped them all out.
Each subsequent time though I've had different results which in the main were as a result of how the players used the motivations to drive their characters to achieve whatever goal they had. The motivations largely drove the momentum of the game to reach a conclusion whether that was a positive one for the characters or not!