If you code software for a game, you will own the copyright in your code. The idea for a book you’re yet to write though does not create any copyright because it’s still an idea that hasn’t been expressed.
Copyright is enforceable as a legal right in the courts, so if someone copies the whole or a substantial part of your work without your permission, you may be able to apply to the Court for an injunction (this prevents their continued use of your work). And if you have lost money as a result of this illegal copying then you can also apply for damages or an account of profits (to compensate you for your loss). For further information click on Related Links.
In most other cases even though your work is now public on the internet and other people can see or enjoy it, you still have the right to decide how they can use it. You should think about the questions in this section, particularly what you want other people to be able to do with it.
The terms and conditions of a licence can cover what your work is used for, for how long, whether or not you should be credited and whether you want to charge a fee for the use. You don’t need legal qualifications to do this as the copyright owner, but it’s important to understand the terms and conditions you are agreeing to. Legal advice can in some instances help with this.
Alternatively you could allow other people to use your work by making it available under schemes similar to the IPO's licensing support resources or Creative Commons for certain uses.