Choose a type of class u wana be.
Heros:Your captin's ship crashed and you discover a city so you walk in it and saw a guy got ripped open, than you heard a monsters voice, than you walk and saw a small base full of scared survivors, you hear a humungous army of zombies than saw them, you start to guard the survivors, the rest u make the story.
Infection:Be a zombie and infect and kill people.
survivor(citazen survivor):Your haveing a fun walk on the park when u saw zombies come so u run panic but nobody belives u so than the next day u saw almost everyone a zombie, the rest u make the story.
Alien:Ur a big alien killing, well zombies and citazen.
survivors(like heros):ur a hero of the city trying to find some survivors and defending urself,the rest u make the story.(BONUS story:you found out that everyone got infected os than u found a helicopter, boat, ect. and tried to get ,n to the ride than u escaped safely,u make the rest if u want)
Thats all, hope u have a cool roleplay.
My type of roleplays dont need rules(but this city needs to be extremely bug like it fills the half of the planet(almost))