Flux & Fission

You are building a power grid, and everything you make either feeds it or feeds on it.

FLUX & FISSION is a tech-only progression modpack for Minecraft 1.20.1 (Forge) built on three pillars, each with one job:

• Thermal Series – the workshop. Ore processing, alloying, fluids, and your first dynamos.
• Extreme Reactors (the Big Reactors lineage) – the power plant. Passive reactors, then steam turbines, then a closed fuel cycle that reprocesses reactor waste into Blutonium.
• Applied Energistics 2 – the brain. ME storage, logistics, and autocrafting that grows hungrier the bigger your grid gets.

Supporting cast: EnderIO conduits, RFTools Builder, Flux Networks, CC: Tweaked reactor automation, FTB Quests/Teams, and a tuned Ex Deorum start. No magic mods. No kitchen sink. No competing tech suites duplicating each other’s jobs.

A world that makes you dig

• Scrubland spawn: dry, near-treeless terrain. There is exactly one tree within 75 blocks of spawn. Guard it.
• Biodiversity is earned: every tree species beyond oak exists only as sieve results. Your first real project is an arboretum.
• STRATA ore layers: the surface is deliberately poor. Thermal metals live in the shallow strata (about Y60 to Y0). Reactor fuel – Yellorium – only exists in the deep strata (about Y-32 to -64), with the lava and the dark.
• Sieving gives a start, never a shortcut: a tuned Ex Deorum provides saplings, seeds, first food, and a modest trickle of iron and copper. Everything else comes out of the ground, through machines.

The five acts

1. Ignition – a Thermal workshop and your first steam dynamo.
2. The Power Crisis – dynamos stop scaling. Time for a small, hungry reactor.
3. Going Digital – Certus Quartz and your first ME network.
4. Steam Age – an actively cooled reactor, a turbine hall, and a closed fuel cycle.
5. The Grid Heart – one final craft demanding the best of all three pillars. Place it, and the grid is complete.