Slime Pen
The Slime Pen holds one jarred slime and collects its slimeballs on a fixed timer. It is the main way to farm resources. You can see the slime inside the pen, at its own size and color.
Slime PenThe interface
| Slot | What goes there |
|---|---|
| Left column | Up to two speed upgrades |
| Top middle | A filled Slime Jar |
| Bottom middle | The slime's food (optional) |
| Right grid | Output: 9 slots of slimeballs |
Hover an empty slot in game to see what it is for. The arrow fills as the current batch progresses. If the pen stops, a red message in the top-right corner says why. With JEI installed, click the arrow to see every slime's production.
How production works
- Every batch adds as many slimeballs as the slime's size to the output.
- A batch takes the slime type's pen time: from 1 minute for tier 0 up to 10 minutes for Netherite. See Slime types.
- When the output is full, the pen waits until you take something out.
- The slime never dies and never leaves the pen, and it keeps working without food.
- Hoppers and pipes can feed it and empty it. See Automation.
Food (optional)
Put the slime's own food in the food slot to make it work faster. When the slime is hungry it eats 1 food item, and that item keeps it fed for 4 batches. Fed batches run twice as fast, including the batch already in progress when it eats. A green 2x under the arrow shows the slime is fed; hover it to see how many fed batches are left.
Without food the pen still runs at normal speed, so food is a boost, never a requirement. Food for a different slime type is not accepted.
Because one item lasts 4 batches, feeding always pays off. A size 1 Diamond Slime eats 1 diamond and returns 4 Diamond Slimeballs, which squeeze into 4 diamonds.
Speed upgrades
Speed Upgrade
Advanced Speed Upgrade| Upgrade | Batch time |
|---|---|
| Speed Upgrade | × 0.8 (25% faster) |
| Advanced Speed Upgrade | × 0.5 (twice as fast) |
Two upgrades multiply together, and food multiplies on top. Two Advanced upgrades plus food bring a batch down to 1/8 of its normal time. A batch never takes less than 1 second. The same upgrades also fit the Slime Squeezer.
Calculator
Rates are per real-time hour (72,000 ticks) while the pen's chunk is loaded.