You can check out the whole Nintendo Direct Splatoon segment above, including the slick Octo Expansion trailer, but let's break it all down.
The 3.0 update, which is free, will add over 100 new pieces of gear and some free new stages including Piranha Pit, Camp Triggerfish, and Wahoo World. Plus, players interested in climbing the ranks with their supreme skills can now make their way to Rank X, which goes beyond the top S+ rank.
The biggest news, though, is the Octo Expansion, the game's first paid DLC. It's a single-player expansion that features new playable character Agent 8. Octo Expansion will also introduce Octolings as playable characters. You can pre-order the DLC on the eShop now.