LIQUID SIMULATION
Fluids as simulated substances — water that flows, fills, and drains; lava that spreads; oil that floats and burns — governed by volume and gravity rather than painted-on effects.
- SOLO-DEV COST HIGH
- TIMING REAL-TIME
- COMMON IN COLONY-SIM · SANDBOX · SURVIVAL · SIM
Dwarf Fortress's fluid mechanics enable player-built plumbing, drowning traps, and catastrophic aquifer breaches; Minecraft's simplified source-block flow became a generation's intuition for game water; Terraria and Oxygen Not Included run volume-conserving liquids that make containment and piping real engineering; and Noita simulates every pixel, liquids included, as its whole premise. Designers simulate liquids because fluids are the ultimate emergent material: they route themselves, find gaps, combine (water meets lava makes stone), and convert level geometry into hydraulic problems — enabling player creativity (canals, cooling loops, death traps) no scripted system could enumerate. Liquids also create distinctive failure drama; the flooding fortress is a story generator. Key decisions: fidelity tier — cellular-automata blocks (cheap, stable, gamey) versus pressure-and-volume simulation (rich, expensive, exploitable) versus true fluid dynamics (rarely worth it); whether liquids conserve volume (crucial for engineering play, dangerous for performance); and which liquids interact and how. Pitfall: simulation fidelity beyond interaction fidelity — gorgeous flowing water the player can't redirect, dam, or exploit is just an expensive material shader; conversely, exploitable liquid physics with bad performance turns every large-scale water project into a slideshow, punishing exactly the ambitious builds the system exists to enable.