Things You'll Need
Instructions
Play or read about other pen and paper role-playing games. Think about the elements of these games that you like and figure out how you could fit them into your own game. Be aware of things like character attributes, character leveling, story progression, achievements, etc.
Write a brief back story for your game. Provide details that would interest other players and give them a motive to play the game. As you write, be sure to stick to your genre, although blending genres can also be entertaining.
Design the character base for your game. Decide how many different kinds of characters should there be and what attributes or statistics do you want each character to have -- for example, does a troll character have more strength or health than a dwarf character? Determine how these attributes will affect the kinds of things each character can do and decide how characters can gain or improve their attributes.
Create a battle system and/or a way to decide the outcomes of players' actions. This could involve dice or it could be based strictly on verbal argument -- it's up to you. You should also decide if characters will be fighting against each other or as a group and determine how they will actually be battling -- for example, magic, weapons, puzzles, etc. Thinking about the genre and the back story of your game should help you out.
Set a goal for the players that is related to the game's story. This could be a group goal or it could be a series of individual goals, or both. Think about what each character can do and how that character's actions will affect the progression of the game as a whole.
Write down the rules of the game and explain them to each player before you are ready to play. Be sure to clearly define what each character can do and to state the main goal of the game.