Acid
Acid is a glowing green liquid that eats wood, metal and stone without being used up, and destroys itself only against water.
- Movement
- Liquid — flows and levels out
- Weight
- 3 / 9 (heavier sinks through lighter)
- Lifetime
- Permanent
- Glow
- Faint
Acid flows exactly like water and has the same weight, 3. It has a faint glow, which makes leaks easy to spot in a dark scene. Oil floats on it, and every powder sinks through it.
It has four reactions and no others. It removes a touching wood cell 30 percent of the time per check, metal 25 percent and stone 15 percent; in all three cases the acid cell survives, so a single pool keeps eating as long as it has something to eat. The fourth partner is water, and there both cells become steam half the time the pair is checked.
What acid leaves alone matters just as much: wall, sand, salt, ash, seed, gunpowder, ice, plant and oil are all untouched. A wall cup holds acid indefinitely, and a pool resting on a sand floor never sinks into it, because the sand is heavier and is not on the menu.
Real acids are selective too. Most attack metals and carbonate rock while leaving glass alone, and they are diluted by water rather than bursting into vapour. The steam reaction in Sandlab is a stylised stand-in for neutralisation, with no gradual dilution and no heat.
Try it yourself
- Striped block. Paint a thick block made of horizontal stripes of wood, metal and stone, then place acid on top. It falls through the wood stripe quickly, slows at the metal and slows again at the stone, so the three rates show up as three different speeds.
- Sand on the bottom. Drop a heap of sand into an acid pool. The sand reaches the floor and stays there as a yellow mound, unchanged however long the acid washes over it.
- Moat around a hut. Surround a wooden hut with a ring of water and pour acid toward it. The leading edge of the acid fizzes into steam at the moat; only once the water is used up does the rest reach the wood and start eating it.
Reactions
Odds are per contact check: each tick, touching cells inside the same two-by-two block are checked against the reaction table, so even a small chance happens soon after contact.
When acid touches something
- Touching Metal: dissolves the Metal. (steady, 25% per contact check) →
- Touching Stone: dissolves the Stone. (steady, 15% per contact check) →
- Touching Wood: dissolves the Wood. (fast, 30% per contact check) →
- Touching Water: turns into Steam, and the Water turns into Steam. (fast, 50% per contact check) →
Tip
To stop a spill, meet it with water rather than a barrier. Each acid cell that reaches the water is gone, while a stone or wooden barrier only buys time.