Modded biomes

Usually, yes. If the biomes come from Forge or Fabric worldgen mods, your client needs the same mods to load the blocks and biomes correctly. If the server uses datapacks or plugin-based worldgen that stays within vanilla blocks, you can often join with a vanilla client.

Plan on real distance. More biome variety usually means more targeted hunting, especially for rare regions. Most communities lean on maps, coordinates, and some kind of travel network (nether highways, waystones, warps) to make repeated trips practical.

It can slow fresh chunk generation, and that gets worse when many players are exploring at once. Better servers offset it with pre-generated regions, tuned view/simulation distances, and rules that discourage high-speed chunk generation sprees.

Both exist. Some servers treat them as an exploration and building upgrade with mostly aesthetic blocks. Others gate resources, spawns, structures, or recipes behind specific biomes, turning scouting and claiming territory into part of progression.

Core mechanics still apply, but your best plan often changes. Terrain can make farm placement harder, biome-based spawns may push you to build in multiple locations, and new plants and trees can shift early food, trading, and building materials.