The following information comes from Ubisoft's blog page:
How sharp are your Mario + Rabbids Kingdom Battle tactics? Sharp enough to test against another human player? You’ll be able to find out on Friday, December 8, when the free Mario + Rabbids Versus mode arrives. Pitting you against a friend on the same system (and playable either with two controllers or with a pair of Joy-Cons), Versus challenges players to hand-pick their three-hero squads, and use every attack and technique available to them to claim victory across small, surprise-filled maps.
There’s a catch, however. Each player has just three available actions per turn, and how you decide to invest them is a big part of the strategy here. You may be accustomed to moving, attacking, and using techniques for each of your heroes during every turn in the campaign and co-op, but Versus is a different story. Will you move all your characters into strategic positions, or will you spend all your actions to, say, move Luigi into a sniping spot, activate his motion-attacking Steely Gaze, and then open fire on a juicy target? Whatever you do, you can bet your opponent will be watching your every move, so be careful not to leave yourself vulnerable.
Versus mode’s selectable combatants are evenly matched, from a skill-point standpoint. Instead of your leveled-up campaign characters, both players can choose from beefy, upgraded versions of all eight characters. You can stick with the solid all-around starter loadouts, or you can specialize using one of 16 unlockable variants (like Rabbid Luigi’s Vampiric option, or Mario’s BIG Stomp loadout), each with differently balanced stats and weapons. And yes, you can pick an all-Rabbid or all-Mushroom Kingdom team. Little things can make a big difference in these matches, and grabbing the optional power-ups (scattered across the map in question-mark blocks, of course) can swing the balance of a match by adding an extra action to a turn, buffing your attacks, and more.
There’s a lot of depth to uncover in these matches, but they’re also meant to be short and snappy – and if you’ve got a short attention span or just want to pump up the challenge, you can limit matches to seven or 10 turns, and set short, medium, or long time limits on those turns. And just to be sure that things heat up near the end, there’s the Showtime option, which kicks in as the match nears its end and turns regular items into super items, while also opening up new ways to get around the map, like pipes or trampolines. If one team is on the ropes, these are a potential lifeline that can yank them back into the lead.
Versus mode will be available December 8 as a free download for owners of Mario + Rabbids Kingdom Battle on Nintendo Switch.