Magpie Games is producing a tabletop roleplaying game set in the world of Nickelodeon animated series, Avatar: The Last Airbender and The Legend of Korra. There's an endless amount of adventures players can go on, but no details are available yet for how the mechanics will work with bending.
According to the announcement, the core book will be released in February 2022, with two supplements to follow in August 2022 and February 2023. They will be titled Republic City and The Spirit World, respectively. Aside from that, there's very little information about how the Avatar TTRPG will play -- but there are a few ways bending could be incorporated.
Potential Bending Systems
Bending in the Avatar tabletop game could be done similarly to how the magical system functions in Dungeons & Dragons 5e, or even in Powered by the Apocalypse. In the former, basic bending could be done freely, like cantrips, while more powerful or stronger bending would require a spell slot of sorts. As the character levels up, these bending techniques could have increased effects or damage, and characters can potentially learn more ways to bend.
In the latter, bending could work on a scale, so players would state what they want to do, roll the dice, and learn the outcome based on their result. This wouldn't require spell slots and would allow players more freedom to bend at will, but would potentially give consequences if they fail a roll.
Combat set in the world of Avatar: The Last Airbender and The Legend of Korra is fast paced, so assuming it will be turn-based in the tabletop roleplaying game, the rules will still need to allow for reactions and opportunity attacks, at bare minimum. Bending itself is used just as often for defense as it is for offense, and it can also be used outside of combat -- similar to magic in other TTRPGs. In this world, people are either benders or non-benders, which will also allow for flexibility in playstyle.
Different Types of Bending
Similar to class systems in other tabletop games, the Avatar game separate elements into classes and it could have subclasses, as well. Earth, air, water and fire could all be bending classes. An example of subclasses would be metal and lava for Earthbenders: Players could specialize in these and learn special skills or do extra damage. This could also introduce Spirit bending through Water, as Unalaq and Korra have done. Very powerful NPCs could bend lightning, and depending on the leveling system, firebending players could potentially learn to do so as well.
One aspect that would be amazing to see is the possibility of being able to combine elements together, or dual bending. In the animated series, both water and Earthbenders can manipulate mud, which combines the two elements. Another example is rocks that have been coated in oil and set on fire.
Depending on the narrative, Magpie Games may not include airbending as a class in its Avatar tabletop game. Perhaps players could unlock this through a special quest or mission, or it could be the whole purpose of the story: To find the last airbender. Whatever is or isn't included, players and GMs can always create house rules or homebrew mechanics to customize the game to their liking.