26.2 Despawn Timer and Age Inheritance

Despawn Timer & Age Inheritance (MC 26.2)

This document details the despawn lifecycle, tick-to-second conversion math, youngest age inheritance rules, and farm production safeguards in Item Clumps for Minecraft 26.2.

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📊 Feature Infobox

Property	Specification
System Name	Youngest Age Despawn Preserver
Vanilla Despawn Threshold	$6,000\text{ ticks}$ ($300\text{ seconds} = 5.0\text{ minutes}$)
Age Inheritance Rule	$\text{age}_{\text{merged}} = \min(\text{age}_A, \text{age}_B)$ (Youngest item wins)
Pickup Delay Rule	$\text{pickupDelay}_{\text{merged}} = \max(\text{pickupDelay}_A, \text{pickupDelay}_B)$ (Longest delay kept)
Target Field	ItemEntity.age and ItemEntity.pickupDelay
Idle Despawn Behavior	Standard 5-minute timer counts down when no new items merge

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⏳ Tick-to-Second Timing Math

In Minecraft, entity timers run at 20 ticks per second:

$$1\text{ second} = 20\text{ ticks}$$ $$1\text{ minute} = 60\text{ seconds} = 1,200\text{ ticks}$$ $$5\text{ minutes} = 300\text{ seconds} = 6,000\text{ ticks}$$

In vanilla Minecraft, an ItemEntity increments its internal age field by $+1$ every game tick. When $\text{age} \ge 6000$, the item is permanently discarded from the world.

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🛡️ The Youngest Item Safeguard Rule

When two items merge in Item Clumps, the surviving entity executes:

$$\text{age}_{\text{merged}} = \min(\text{age}_{\text{this}}, \text{age}_{\text{other}})$$

  Existing Ground Clump                           Newly Dropped Item
  - Count: 500 Cobblestone                       - Count: 1 Cobblestone
  - Age: 5,800 ticks (4m 50s old)                - Age: 0 ticks (Brand new)
                 │                                              │
                 └──────────────────────┬───────────────────────┘
                                        │ (Item Clumps Merging)
                                        ▼
                           Merged Mega-Stack Entity
                           - Count: 501 Cobblestone
                           - Age: min(5800, 0) = 0 ticks (Fresh 5-minute timer)

Why This Protects High-Yield Farms

• The Problem with Vanilla Lifespans: In vanilla, if you have a slow collector, newly dropped items merging into older items could be deleted 10 seconds later if the host entity was already 4 minutes and 50 seconds old.
• The Item Clumps Solution: Continuous item flow in active mob grinders, automated tree farms, or quarry drill lines repeatedly refreshes the clump age to 0. As long as the farm is actively generating items, no items will ever despawn.
• Idle Cleanup: Once the farm stops producing items, the clump sits idle on the ground. The age timer ticks up uninhibited from $0$ to $6000$, safely cleaning up all uncollected items after 5 minutes of inactivity to prevent long-term world file bloat.

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🛑 Pickup Delay Safety

To prevent players from instantly re-absorbing items they just dropped from their hand, Minecraft assigns a pickupDelay (typically 40 ticks = 2 seconds).

When items merge:

$$\text{pickupDelay}_{\text{merged}} = \max(\text{pickupDelay}_{\text{this}}, \text{pickupDelay}_{\text{other}})$$

This ensures that if a player deliberately throws an item on top of an existing clump, the clump will not instantly vacuum back into their inventory until the full pickup delay expires.

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💻 Ground-Truth Java Source Implementation

From ItemEntityMixin.java in Minecraft 26.2:

// During Complete or Partial Merging:
this.pickupDelay = Math.max(this.pickupDelay, ((ItemEntityMixin)(Object)other).pickupDelay);
this.age = Math.min(this.age, ((ItemEntityMixin)(Object)other).age);

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🔗 Related Documentation (MC 26.2)

• 26.2 Mega-Stack Clumping
• 26.2 Hopper Integration
• 26.2 Architecture & Mixins