Copyright arises naturally as soon as someone commits text to paper or computer screen. The copyright to the text of this conversation is owned by me! However, it is a very weak right and the burden of proving copying and direct financial loss because of the alleged infringement is very high.
There is no copyright in ideas per se until they are written down on paper.
Works such as book and film plot lines are protected by copyright, but it is very difficult to win these types of copyright infringement cases as long as the copying creators change enough of the plot, characters and dialogue so as the general reader, listener or viewer will know that the copied work is not by the same authors and is not a sequel or “spin-off”. There is a lucrative market in Direct-to-DVD “Mockbusters” which are clearly ripped-off from big budget Hollywood franchises: “Atlantic Rim” -v- “Pacific Rim” and “Transmorphers” -v- “Transformers” (!). Many a pulp novel writer has made a career out of stealing better authors’ ideas without being successfully sued. Dan Brown successfully defended a copyright claim by the authors of “Holy Blood, Holy Grail”, the pseudo-historical book on the alleged real-life and genealogy of Jesus upon which Brown based the plot of his smash hit thriller, “The Da Vinci Code”.
There is also the risk of a competitor suing you under the Tort of “Passing Off” if your respective works are sufficiently similar to create confusion in the minds of the public to the extent that you are exploiting the other business’s goodwill in a way that could injure it.
Registering a piece of Intellectual Property as a Patent, Trademark or Design Right means that it is automatically protected from all other similar designs and the Right Holder does not have to prove deliberate copying by the other party.
You should investigate your competitors’ designs and images carefully to check whether they are protected by UK or International Trademarks, Design Rights, Patents and Creative Commons Licences. The creators’ own websites should assert what special IPRs protect their works and you can also search the following websites:
UK Intellectual Property Office: https://www.gov.uk/government/organisations/intellectual-property-office
World Intellectual Property Organisation: https://www.wipo.int/portal/en/index.html
EU Creative Commons: https://creativecommons.org/