I'm seeing a few people asking about the game modes on Discord, so I thought it would be a good idea to create a post listing all of them and explaining how they work.
This Format arose from the September 2024 Format Challenge set up by the GU team on Discord:
It was proposed by protoaddict. According to them, most TCGs implement a version of Singleton at some point, once the card pool is deep enough. And it happens to be a game mode protoaddict usually enjoys, hence the suggestion.
All cards are allowed in this format, the single rule is that only one copy of every card is allowed. This format has been touted by some people as one the most fun game modes currently available.
This Format also arose from the September 2024 Format challenge. It was initially proposed by the Zeal team. The one rule is to ban every card in the top 500 ranking, so only the least popular cards would be available to play.
The idea behind Underdog was to create a format that cuts out all the meta decks. Team Zeal's first thought was to make a hand-curated list but that seemed like a daunting and time consuming task. That's when they came up with the alternative of banning the top 500 cards.
Gzitch from Team Zeal suggested using the data available on https://cardsunchained.com/ for the ban list. My understanding is that the ranking is calculated based on the number of matches the card was included in a deck. However, this list taking all games from all modes into consideration, it doesn't distinguish between Formats and Ranked. So the final list is somewhat distorted, where some Mutation cards for example were being allowed in Underdog while being quite meta in Ranked.
The second time Underdog was rotated in, more than a month later, the GU team just announced the Format, didn't ask Team Zeal for an updated list, and went live with the old one that had the Mutations cards. At this time, they asked Jammy to replace the old list with an updated one.
Because the change was done after the Format went live, other players got upset and Team Zeal had to explain what was being done and why. Someone pointed out that the data from cardsunchained.com was polluted by Formats and not even accurate for what were the goals of Underdog. So hrpoonloue vowed to get it right for the third go around!
And thus, to fix this situation hrpoonloue reached out to 
I'd like to acknowledge the help from Team Zeal's hrpoonloue and Guillotine in collecting the information for this section.
Me and 
We called it 'Power Surge' and the rules were:
Mana wheel starts at 5
Ban all cards with 4 mana or less
High mana cost banned cards:
Replicating Ratification
Aurora Oblivion
Tendrils of Dread
Lost in the Crowd
Hortuk, Fallen Commander
Our objectives with this idea were to create a high power and fast game experience where we skip the early game and give a new life to high mana cards that see almost no play, like for example high mana Atlanteans or Guilds creatures. It would also make 9 mana creatures attractive again, prevent pretty much any annoying deck (LitD Coronet, Carvings, Vespids, etc.), and create faster matches that could end abruptly with a lot of damage dealt in each turn.
It seems the GU team actually liked the idea, but there were some technical limitations that were precluding implementation. However, they made changes to enable starting the game at 5 mana and surprised us all when they announced the mode would be rotated in! The first week ever started on the 24th of February.
We looked at the balance and made some adjustments. To read a bit more about the history of the Format and card bans you can expect for the future, please take a look at this other post.
The GU team introduced this Format. This and the other Formats they introduced fall into a category of simple and obvious rule changes to the game's original ruleset. They're all in the direct lineage of game mode variations offered by other TCGs.
The rule in this game mode is: only Common Quality cards are allowed.
This Format was also introduced by the GU team. You are allowed to play with cards from the three most recent expansion Sets, plus Welcome and Core. Mini-sets are included (like Tower of Dread and Fallen Age, as they were released afterward), but do not displace the major expansion Sets.
While Tides of Fate is in rotation, Food Chain is banned.
And this is the official introductory blog post:
https://content.godsunchained.com/blog/article/new-format-block-constructed
Standard was also introduced by the GU team. It is a flexible Format - without fixed Set rules, and is still being experimented on. At first glance, it can share some similarities with Block Constructed. The Format focused on the latest expansion Sets.
"[The] Goal is to make a viable modern format that allows us to print new cards without powercreeping insanely due to the massive [number] of cards in the wider meta. Whatever we end up with will reflect that.":
The Format aims to be attractive enough that it can become available permanently on weekdays, once the number of active players allows for offering more game modes without making queuing times too long. The 2 iterations we had so far were:
The Genesis Format was also introduced by the GU team.
In this mode you can only use cards from the sets Welcome, Core, Etherbots, and of course, Genesis.
And this is the official introductory blog post: https://content.godsunchained.com/blog/article/flashback-genesis-is-here
The Divine Order Format was also introduced by the GU team.
In this mode the original set restrictions were Welcome, Core, Genesis, Etherbots, Trial of the Gods, and of course, Divine Order.
And this is the official introductory blog post:
https://content.godsunchained.com/blog/article/flashback-divine-order-and-formats-primer
I hope you found this information useful. Thanks for reading!
