What Red Eclipse is
Red Eclipse is a free and open source arena shooter built on the Tesseract engine, a modern deferred pipeline engine with realtime dynamic lighting, shadows, HDR, screenspace reflection, and dynamic organic model deformation. The focus is fast, agile, easily accessible first person shooting, with seven unique main weapons to pick from. Movement is a big part of the game: parkour, impulse boosts, dashing, and other tricks let you move around arenas quickly rather than just walking and aiming. The project has been in active development for over 15 years and everything, engine and assets alike, is freely available to copy, modify, and redistribute. It runs on Windows and GNU/Linux.
Playing together
Red Eclipse ships with online PvP and online co-op, so a group can jump into matches against each other or team up. There is a large set of mutators and game altering variables, which means your group can change how a session plays and settle on a ruleset that suits everyone. Beyond fighting, the included realtime multiplayer editor lets you create maps with other players in co-op edit, so building a level together is a mode of play in its own right. The full power of the Tesseract engine is available in that editor, so what you make is not a stripped-down toy version of the game's tools.
Before you start
Expect a shooter with a steep ceiling: the game aims to be fun and easy to pick up while still having elements to master, so movement tricks and weapon handling reward practice. It is tagged as violent and includes gore, which is worth knowing before you pass the keyboard around. The project is volunteer run, with servers and infrastructure maintained by volunteers, and there are no fees, microtransactions, or lootboxes. The community keeps a standard of friendly behaviour and invites contributions, so if your group wants to shape maps, modes, or settings, that is part of how the game works.