Sumo Tournaments

Sumo Tournaments are occasional competitions that the developers host on Twitch. In these tournaments, you build a Sumo tech within the corporation restriction of one of three leagues, and your tech is battled against the champions of that league. If a tech beats all of the champions, and the other winners if there are any, then the creator wins a prize from the developers. These prizes can vary, but they are usually a code for the full game, or a code for R&D if they already own the game.

Leagues
Currently, there are three Sumo Leagues: Little League, Middle League, and Big League.

In this league, techs are small, light, and often fast. Due to their lower health, as they don't use GeoCorp blocks, they tend to be destroyed much faster. As such, techs tend to try to win the battle as fast as possible rather than trying to hold out until their enemies are destroyed. Tanks are uncommon, while Pushers and Matadors are pretty common. Jumpers are more common than in the other leagues, as techs are lighter.
 * Little League - GSO only

In this league, techs are pretty large and reasonably heavy. As they don't have access to the boosters of GSO, techs are usually pretty slow, and many tactics are hard to use. Matadors are very difficult to build, and Jumpers are impossible. And since there are no guns to use, techs solely use Melee to deal damage. As such, matches in Middle League tend to be much longer than matches in the other leagues. Without boosters, almost all of the techs in this league are either Tanks or Pushers. The tanks simply try to last longer than their enemies, while the pushers make heavy use of GeoCorp Two-Scoop Loaders to lift their enemies out of the arena.
 * Middle League - GeoCorp only

The Big League is what you can consider to be the purest of all the leagues. In this league, there are no restrictions to the blocks you can use, so any build goes. Any tech from the other two leagues can be put into the Big League, though this is very uncommon. Instead, techs in this League tend to be larger and heavier than techs in the other two leagues, though they are usually slower than techs in the Little League. You will see most types of techs fairly often, though Jumpers aren't as common do to the generally heavier weights.
 * Big League - No Restrictions

Big League
See also: Sumo Showdown