I’m seeking guidance on a question related to my current project. I’m working on a crowdfunding campaign for a roleplaying game. For the sake of example, let’s call it Mordor: The Roleplaying Game. On the campaign page, I’ve used the full title, but I would like to start referring to it in short form as Mordor RPG, in sentences such as: “In Mordor RPG, you battle monsters and complete quests.”

A native English speaker pointed out that using the title this way might feel non-standard or awkward to potential readers unless I add the definite article—i.e., The Mordor RPG. However, other native speakers I consulted found that phrasing clunky.

Since I’m following the Chicago Manual of Style, I looked for guidance there. While some general inferences can be drawn, I couldn’t find an exact example supporting the use of Mordor RPG without “the.”

I’ve noticed some variation online: e.g., the crowdfunding campaign for the Cosmere roleplaying game consistently uses the Cosmere RPG, whereas Avatar: The Roleplaying Game is sometimes shortened to Avatar: The RPG. However, I haven’t found examples of a short-form title like X RPG used without the article.

To offer some food for thought, I can't imagine someone talking about the game The Legend of Zelda: Breath of the Wild by saying, 'I played the Zelda BOTW today.'

Thank you very much for your assistance!