
If you retrieve the serum before he dies, he will immediately give you his radio Rebecca will be with him in the drug room for a while where she can treat wounds if you are poisoned during the first fight with the big snake, Rebecca will get the serum for Chris as a playable character Chris can collect Richard's assault shotgun in the Aqua Ring later and finally, the Plant 42 boss fight will just feature Chris. In Chris' scenario, saving Richard from being poisoned or not has significant influence on the rest of the game. In Jill's scenario, he will then help her defeat the big snake by sacrificing himself in Chris' scenario, he sacrifices himself when he is eaten by a big shark. Finally, in both scenarios, Richard is found and can be saved from snake poison.

Barry briefly appears in Chris' scenario before gameplay starts, but Rebecca is completely absent from Jill's scenario. Rebecca can treat wounds, Barry supplies weapons and ammunition. Chris is helped by Rebecca throughout the game (Rebecca is even a briefly playable character) while Jill is helped by Barry. Jill may use the grenade launcher and Chris the flamethrower.

Chris is more resistant to wounds than Jill and has a better chance at headshots. Chris always has the lighter in his inventory while Jill's takes a slot. Jill uses her own lock pick to open some doors, but Chris needs to find old keys which use slots in his inventory (Jill's lock pick doesn't). Jill has eight slots in her inventory whereas Chris has six.

There are a few gameplay and story differences between the two playable characters.
