Spoilage

Each perishable item or stack carries a freshness value or age that advances each tick at a rate set by item type and storage conditions; at a threshold it becomes rotten, converts into a spoiled item, or is destroyed. RimWorld stops rot for food kept at or below 0 C, so walk-in freezers are standard; Don't Starve moves food from fresh to stale to spoiled and finally to rot, with ice boxes slowing the clock; Factorio: Space Age gives biological items spoil times from about two hours down to a few minutes, cannot be delayed, turns spoiled items into Spoilage, and passes ingredient freshness on to recipe outputs. Inputs: item type, time, storage environment. Outputs: current freshness, value or effect scaling, and spoil events.

A clock on every stockpile. Players stop hoarding and start thinking in flow: produce close to consumption, build cold storage, preserve food, or accept waste. Opening a storeroom to find a harvest rotted is a sharp, memorable loss.

• spoil time per item type
• storage modifiers such as temperature, containers, and preservation methods
• whether freshness is binary (fresh or rotten) or continuous and scales value
• what spoiled goods become: nothing, a waste item, or a useful input such as fertilizer
• freshness inheritance across recipes

• Spoilage that is cheap to stop, such as one freezer that halts all decay, becomes a one-time build tax.
• Short spoil times on items with long logistics routes make some chains impossible without explanation.
• Hidden freshness values make sudden losses feel unfair.

• Shifts optimal play from stockpiling to just-in-time throughput; Factorio's developers state that buffering is not helpful under spoilage.
• Cold storage couples food to power and temperature systems, so a power failure becomes a famine risk.
• Seasonal harvests plus spoilage create a winter preservation problem.
• Freshness-priority handling (pick freshest or oldest first) creates new logistics rules.

• What spoil-time distribution across goods produces interesting routing without making long chains infeasible?