This post is a comprehensive list of all restrictions and guidelines on card design and submission. As it is updated more often than the wiki, and only by the developers, it should be considered the final say in game and submission rules.
The top 10 voted cards of each week are accepted into the game. A query utilizing Reddit's API ensures that the ordering reflects actual upvote amounts and takes vote fluctuation into account as well as possible. Votes from the in-game voting system count as two votes on the subreddit.
Wednesday Midnight PST
The Submission deadline for both normal submissions and design competitions. Cards submitted afterwards will be counted as for the subsequent week.
Friday 10:00 am PST
The Voting deadline for both normal submissions and design competitions. Votes will be counted by the regular dev card review stream on early Friday, and the top voted cards for that week will usually be implemented on the same day.
New cards should be submitted with the [Card] tag and follow all the rules of any post in the subreddit. The top 10 voted card submissions each week are accepted into the game.
Design Competitions / [DCXX]
Cards submitted for a Design Competition should be submitted with the [DCXX] tag, where XX is the number of the week, and follow all the rules in the Design Competition announcement reddit post. DC slots will reduce the available normal submission slots accordingly, so that the total number of accepted cards in a week remains 10.
Updates must be submitted with the [Update] tag, and should have a change in the card's effect visible in the card's stats, numbers and/or effect. A change to how a card works without changing the card's text itself, in order to match its function with its description, is considered a Dev Change instead. The top 3 voted update submissions with more votes than the 10th normal submission each week are accepted.
Cosmetic updates must be submitted with the [Cosmetic Update] tag, and should only change something that doesn't affect gameplay yet. For example, the art, the name of the card, its rarity, or its tribal type if there isn't relevant support for that specific tribal type yet. Cosmetic updates with more votes than the 10th normal submission each week are accepted, with no slot limits.
The developers reserve the right to change card text or effects should they break rules or otherwise surface problematic bugs, depend on new features, etc.
Cards that misrepresent their effects, rely on impossible effects, and/or have significantly faulty code will be disqualified.
Cards are voted on and accepted based on their visible text. In the case of understanding conflicts or rule consistencies, the code is changed to match the implications of the text. Updates that don't change the text of a card can't be voted on.
If a player has a strong opinion about a dev change and has some support on the reddit or discord, they can contact the developers and will be heard out.
Accepted normal and dc submissions, as well as accepted cosmetic updates that changes the art significantly, award an amount of gold each. The player that last saved the link of a submitted card (NOT the listed designer or the submitter) that is accepted into the game receives the reward. They also automatically receive the Blueprint of the card if it is a new card, with a special golden border and a unique play animation.
Accepted mechanical updates, or cosmetic updates that don't change the art significantly, do not provide rewards.