This instructable will guide you through the steps that you should take to make a decent "board" game. The reason that I put "board" in quotations is because this same strategy can be applied to card, dice, or even video games (However, I will not be talking about programming in this instructable.) This is by no means the only way of doing this, it is just the method that I use, and it works well for me, so enjoy.
Step 1: The Concept
The first thing that any board game maker has to think about is the theme of the game. This could be a literal theme, such as zombies or candy, or it could be a mechanic that the game will focus on, such as dice rolling or resource management. Having a solid theme is very important to a good game. For this example, I am going to choose a tile theme, where there are tiles that make up the game board, for randomization and replayability.
Step 2: The Goal
The next step in making your game is to come up with some sort of goal. How do(es) the player(s) of this game win? Or do they just keep playing until they lose? For my example, I have the players trying to fix systems of a broken submarine. Once they fix all of it, they win. Notice that I had a mechanic for my theme in the last step, and so now is when I came up with the setting, in my case a submarine.
Step 3: How Do You Get From Here to There?
This step is all about figuring out how to get to your goal, the one you came up with in the previous step. This is a large step that may take you a while to figure out, because it is the main "meat" of the game, where the gameplay is. In my example, I have players roll a due to move their player piece around the submarine, trying to fix their part of the sub.
Step 4: Flesh It Out
This is where you come up with additional mechanics and gameplay. This will probably be the longest step, and it varies from game to game. For my game, I have tiles laid out, with various broken systems, as well as event and point spaces, and time counters. Players need to fix all of their broken systems, and if they don't all fix their systems once "time" runs out, the game is over.
Step 5: Make a Prototype
This is where you make a playable, but not pretty, version of your game. It will have all of the mechanics and pieces of your game, but it doesn't have to have good pictures, perfectly shaped anything, or be polished at all - this is just so that you can playtest the game. I do not have a picture because I threw away my prototype, but trust me, it looked awful.
Step 6: Playtesting
This step is where you bring your ugly, ugly prototype to someone else and make them play it with you. This will establish a lot, and is very important to making a game: you will probably realize that your game is terribly broken, and you will need to fix probability, numbers, and other things of that nature. In that case, go to step 4 and keep working on your game.
Step 7: Make It Look Pretty and Make Rules
This step is explained in the title: make a finished, beautiful version of the game and write a rulebook. If you did the rest correctly and thoroughly, this should be a small step. Then, enjoy your game!