Mods work in Multiplayer

Mods work in multiplayer.
Procedural generation is mostly client-side, generated in real time with the seed provided by the game. As the seeds are almost never changed by the mods, most mods which change generation are changing the options of which the game selects in generation. As a result, these mods are client-sided, changes by which other players in the same session will not see without the same mod installed.
Terrain mods will not sync between clients as terrain is generated client-side, however, terrain changes made with the Terrain Manipulator will sync, resulting in possible floating balls of terrain to others.
Flora and rocks will not sync between clients as they are generated client-side, but the destruction of commonly generated flora and rocks will sync.
Animals will sync between clients. It is because of the seeds for the animals are generated with the planet seed, of which the generation options can be changed. The positions and seeds of the modded animals are synced. However, as the modded animals spawn only around the modded player, other players may only see the modded animals when in proximity of the modded player. If the client also has a terrain mod installed, the animals may also float in the air for other players. If the modded player is the host of the session, the modded discovery data will also be synced across players, resulting in players without the mod not being able to discover certain modded animals.
Colours will not sync between clients. The colour options and the generations are client-side only.
Technology changes depend greatly on the way the tech is modified. If a vanilla tech is modified with new or modified values, the effects will be synced from the modded client to the other players. It is because the damage and otherwise effect data are simply sent from the client and received on the other end. If the tech uses custom made, new projectiles, other players will not see the projectile, but will feel the effects of it.
Base objects will not sync between clients, as the base object placements are based on their IDs, modded objects will not show up for other players. Any already existing vanilla objects will still be visible, as they are already in the game.
Character model parts will sync between clients as long as the model is an existing vanilla model. Otherwise the respective parts will be invisible to other players.
Animations are synced between clients as long as the animation ID exists on both clients.
If the other players are using the same modded files, the generation and otherwise experience will be identical.
MODS DO NOT IN ANY WAY HINDER THE ABILITY TO CONNECT TO OTHER PLAYERS' GAMES.