Included

Incorporated into FU

 * Frackin' Races
 * Augment Extractor
 * Bees!
 * Dungeoneer Dungeons
 * Extra Dungeons
 * Harvester Beamgun
 * Kirhos
 * Legacy Dungeons
 * Legacy Monsters
 * Mantizi Race
 * Mech Overhaul
 * Memento Mori
 * Nightar
 * Peglaci
 * Prop Pack
 * Skath
 * Slime Race Mod
 * Starbooze
 * ztarbound
 * Pandora's Box (partially)
 * Racial Shop Counters
 * Racial Kitchen Counters
 * Foodie's Furnitures
 * Frontier Expansion
 * XCustomCodex
 * Automation Aides
 * Classical Weaponry (partially)
 * Terrain Tweaks

Originally implemented into FU, or at least similar to it

 * Aimable Shields or similar mods - all shields in FU are already aimable, so these mods are not needed with FU. Shields from other mods won't necessarily be aimable (it's up to the mod that adds them).
 * Any race extender (xbawks, etc.) - FU already has a race extender, so there is no point to install a separate mod for it.
 * Any mod that allows you to build your own ship - FU already has this. No matter what, do NOT install another mod that does the same or similar thing. Most notably, a standalone BYOS mod is completely different from FU BYOS (only the name and purpose are similar, but implementation is not), so having it installed alongside FU will break things.
 * Any mod that adds bonuses and traits to vanilla and FU races - FU already has this, though any mod that adds a status effect buff as a 'race trait/bonus' should still be safely compatible (EXCEPT Frackin' Races), for example this mod or this should still work. However installing such mods means you will have traits and bonuses from both mods, making you more powerful than usual. You can disable FU's racial traits and bonuses in SAIL.
 * Any mod that adds machines that collect, extract, or generate resources - FU has such machines; pumps, quarries, extractors, sifters, rock crushers, and centrifuges. It should still be fine to install another one, as long as its completely independent from FU, because modifying FU's machines is risky.
 * Field Generator - FU already has it. Having it installed alongside FU shouldn't break things, but there is no point to do so.
 * Any mod that allows you to play as Fenerox - FU already made it playable. See this page.
 * Any mod that allows you to play as Shadow AKA those black NPCs you encounter in Midnight planets and biomes - FU already made it playable. See this page.
 * Enable Monster Special Attacks - FU already does this
 * Earth's Finest - FU already includes the changes from this mod
 * Mods that allow you to collect more rock types like this or this - FU does this already. There's simply no point installing it.

Installing mods that are already included (even if only partially) can either have no effect, have duplicate items and interactions, or make the game unstable. You may also want to check out a list of incompatible mods.

Frackin' Universe makes its own changes to some of the included mods, which is even more reason not to install included mods.