Related activities should be kept to their respective subs unless there's a very valid reason For custom card game questions, it would be better for their respective target audience's subreddits.
Redirection of any means out of the subreddit with the intention to promote a product, a service, a shop, another webpage, or events that are running, i.e.
Everything related to playing cards: Questions, collecting, news, reviews, Kickstarter campaigns, hobby projects, and more.
