The game developers I talk to are always worried about protecting the idea for their game. Whether they have a novel form of bullet hell or a new take on rogue-lite, developers are constantly afflicted with a fear that someone will steal their idea. The unfortunate reality is that there isn't one magic bullet to protect an idea. Contract and intellectual property law can provide some protection, but an idea itself is very difficult to lock down. In this post I discuss the advantages and limitations of various ways to protect your game to guide you through this process.
Contract Law (Non-disclosure)
Contract law in the form of confidentiality and non-disclosure agreements is the most direct way to protect an idea that you don't want publicized. A contract is simply a legally enforceable agreement between two private parties, so it does not rely on other areas of law like intellectual property. As a result, most things that two parties agree to (within certain limits) can be enforced by contract. The downside is that contracts only apply to the people who agree to them and have entered into the contractual relationship (or their successors). Lawyers call this contractual relationship "privity."
Therefore, a publisher, partner, or employee could be subject to a non-disclosure agreement (NDA) if they agree to sign, but a third party who has not signed the agreement is free to do as they please. The other obvious downside is that not everyone will agree to sign an NDA, particularly publishers. Also, in California at least, an NDA that is too broad may be construed as a restraint on competition and invalidated on those grounds.
However, NDAs can be an effective tool to protect aspects of your game that you want to keep under wraps. They basically create a penalty for sharing information about the game, which can include specific ideas or game mechanics.
Trade secret law can allow you to recover damages against someone who steals your idea, but you must first have taken steps to protect that idea begin with. This means you took contractual measures like NDAs, as well as physical security measures. It can be useful in a case of outright theft, but similar to contract law, it is useless against a third party who implements the idea independently.
Patents can be powerful tools, but only if you have a patentable idea. To be patentable, your idea must have the following elements: 1) patentable subject matter, 2) novelty, 3) usefulness, and 4) non-obviousness. Purely abstract ideas like "an arcade style bullet hell game with fighting robots," are not patentable subject matter, nor for that matter are they novel or non-obvious. While certain mechanics might be patentable, in all likelihood your game idea is not.
Trademarks protect markers of origin, basically the word or symbol that tells a consumer where a product or service came from. It can protect the title of a game for instance, but not the ideas in the game itself. This protection can still be useful if someone makes a similar game to yours and tries to pass it off as the same, but for that scenario to work your game must already be in the market.
Entertainment companies like video game developers often rely on copyright to protect their works. However there is an important concept in copyright called the idea/expression dichotomy. Copyright does not protect ideas, it protects expression. An angry whaling boat captain hunting for a white whale is an idea, whereas Moby Dick is the expression of that idea. Someone can copy the idea as long as their expression of said idea is not a copy of Moby Dick. In addition, copyright allows for independent creation, although proving independent creation in the connected age of the internet is difficult.
Copyright is still a powerful tool to protect your games as an embodiment of your ideas, particularly once the game is published. Say someone is implementing the same game idea as you. If you can show that they had access to your game, and their implementation is substantially similar to yours, then you still have a case in copyright.
So what can you do?
This post may be discouraging to those of you hoping for the ultimate weapon to protect your game idea. I urge you instead to appreciate the fact that the law does not lock down ideas but rather rewards those who can implement them in the most effective way. Creativity is often iterative, and chances are your idea is not as novel as you might think. The law rewards those who can implement ideas in the most effective way, so rather than worrying about how to lock your idea in a chest in a dark cave, push yourself to bring it to light and share it with the world.