Iron Farm Basics: Villager Panic and Golem Spawns

The panic mechanic, precisely

Iron golems are not farmed by killing them; they are farmed by making villagers ask for one. A villager tries to summon a golem when it is gossiping, or every 5 seconds while it is panicking because it has seen a hostile mob. Every one of the following gates must be open at the same time, which is why farms that "look right" produce nothing:

• It has slept in the last 20 minutes (one full in-game day). A bed inside the pod, reachable, is not decoration — it is a hard requirement.
• It has not detected a golem in the last 30 seconds, scanning within 16 blocks on each axis once every 10 seconds.
• It has not been within 10 blocks of a summon in the last 30 seconds.
• Enough participants within 10 blocks: 3+ while panicking, 5+ while gossiping. This is the number that sets the minimum pod size.
• A valid spawn point exists in a 17×13×17 box centred on the villager (±8 horizontally, ±6 vertically), tried up to 10 times per trigger.

The scarecrow is therefore not a "trigger" in the vague sense: it must be a hostile mob the villager can see, and it must keep existing. That is why a zombie in a minecart behind glass works and a zombie standing in lava does not, and why iron farms fail on Peaceful difficulty — the zombie despawns and the panic state stops.

The rate formula

Once every gate except the last is satisfied, the throughput is set by two timers. Spawn attempts fire at 0.0014 per game tick (1 in 700), which averages one attempt every 35 seconds. A successful summon then locks the village out for 30 seconds, and an attempt only succeeds if one of its 10 random points is actually free.

Let p be the fraction of attempts that find a valid spawn point. The expected time per golem and the hourly rate follow directly:

seconds per golem = 35 ÷ p   and   golems per hour = 3600 × p ÷ 35

Each golem drops 3–5 iron ingots (mean 4) plus 0–2 poppies at a 66.67% chance, so ingots per hour is the golem rate multiplied by 3, 4 or 5. Two consequences fall out of the algebra. First, the 30-second lockout only becomes the binding limit when p is at least 0.857 (30 ÷ 35) — below that, empty spawn attempts, not the cooldown, are what costs you iron. Second, no single pod can beat 120 golems per hour, because that is what a 30-second lockout allows.

Worked example 1: one pod, nothing blocked

Three villagers, three beds, one zombie-in-a-minecart scarecrow, and a clear spawning deck. Take p = 1.0 as the ceiling case:

35 ÷ 1.0 = 35 seconds per golem, so 3600 ÷ 35 = 102.9 golems per hour. At 3–5 ingots each that is 308.6–514.3 ingots per hour, or 411.4 on the mean drop of 4.

That number is the one to compare against your own design, and it is measured, not guessed: run the farm for ten minutes, count the golems, multiply by six. If you are under 102.9 per hour you have blocked spawn space, and the fix is almost always the same — the golem has to be able to stand somewhere whose block and the two blocks above it are non-full and non-redstone.

Worked example 2: the same pod with half its spawn space blocked

This is what actually happens in a first build. Chests, carpets, slabs, a lantern and a hopper column eat into the 17×17 footprint, and only three attempts in four find a legal point (p = 0.75):

35 ÷ 0.75 = 46.7 seconds per golem → 77.1 golems per hour → 231.4–385.7 ingots per hour, mean 308.6. That is 103 fewer ingots per hour than the clean version, from nothing but furniture in the wrong place — a 25% loss.

The lesson is quantitative: the drop from p = 1.0 to p = 0.75 costs you a quarter of your iron, and there is no redstone fix for it. Clear the footprint before you optimise anything else.

Worked example 3: three pods, and why they need 17 blocks

One pod is capped, so throughput comes from multiplying pods, not from tuning one. The constraint is the detection radius: a villager that sees a golem within 16 blocks will not summon for 30 seconds. Put pods closer than 17 blocks apart (16 + 1) and each pod's golem suppresses its neighbours, so three pods behave like one. Space them at least 17 blocks apart horizontally and each runs its own clock.

Three independent pods at p = 1.0: 3 × 411.4 = 1,234 ingots per hour on mean drops. Three pods at a realistic p = 0.75: 3 × 308.6 = 926 ingots per hour. That needs 9 villagers and 9 beds, one scarecrow per pod, and one collection point per pod — and it is the design that ends iron mining for a survival world.

Why farms stop: the 20-minute sleep gate

The requirement people miss is the sleep timer. A villager only summons if it has slept within the last 20 minutes, so a pod whose beds are unreachable, obstructed or simply absent produces until the timer expires and then goes silent — with no error message. The arithmetic bounds the damage: 20 minutes is 1,200 seconds, so a pod that stops sleeping after its last successful sleep can still deliver at most 1,200 ÷ 35 = 34 golems, or 102–170 ingots (mean 136), before output drops to zero.

That is why the diagnostic order for a dead farm is: beds reachable and unoccupied-but-claimed, then the scarecrow still alive and visible, then spawn space clear, then distance from any other village whose golems are inside the 16-block detection radius.

Bedrock Edition uses a different rule set

None of the above transfers cleanly to Bedrock. There, village golems need at least 20 beds and 10 villagers, 75% of the villagers must have been able to work in the past 24,000 ticks (20 minutes), 100% must be linked to a bed, and each extra 10 villagers adds one more golem: 10 villagers → 1 golem, 20 → 2, 30 → 3. The spawn volume is the same 17×13×17, but it is measured from the village centre rather than from each villager, and the space test is a 2×3×2 volume above the spawn block. Copying a Java tutorial into Bedrock is the single most common reason a farm does nothing.

Sources and standards

FAQ