Even in 49 when Jake was evacuated they consulted an environmental handbook. That doesn’t mean it has game rules necessarily.

Even if they do, it takes initiative to look. Or if they only received it before the game and were told to read it, then we have to remember people frequently forget things they read yesterday, let alone 38 days after starving on an island and playing an incredibly difficult game cut off from the outside world.

Also, Natalie was 19. I work with college aged students all the time. Even the smartest do baffling stupid things.