How to Build an Efficient Guardian Farm

A guardian farm is an essential build for players who need large quantities of prismarine shards, crystals, and fish. These materials are crucial for crafting beautiful decorative blocks like prismarine bricks, dark prismarine, sea lanterns, and the powerful conduit structure. This guide will walk you through the process of creating an efficient guardian farm using ocean monuments, which are the imposing, naturally generated underwater structures and the only source of guardians in Minecraft. Building one can seem daunting, but with careful planning and execution, you can harness the power of the ocean's depths.

Basic Principles

Understanding the spawning mechanics of guardians is crucial for building an effective farm. Without grasping these core concepts, your farm might be inefficient or fail entirely.

Spawn Mechanics

• Ocean Monuments:

  • Guardians exclusively spawn within the 58x58x23 bounding box of an ocean monument. This box encompasses the entire structure and the water column directly above and below it. Identifying this precise area is key. You can visualize this box by noting the coordinates of the monument's corners.
  • They absolutely require water source blocks to spawn. Flowing water is not sufficient. This is the most critical condition and the reason monument draining is often a part of high-efficiency farm construction.
  • They typically spawn in small groups of 1-4 individuals at valid spawn locations within the bounding box.
  • Unlike most hostile mobs, guardians can spawn regardless of the light level. Torches or other light sources will not prevent their spawning within the designated water blocks. However, lighting up surrounding caves and the ocean floor outside the monument can help prevent other unwanted mobs from interfering with spawn rates if your farm design exposes those areas.
  • The presence of Elder Guardians within the monument does not directly affect guardian spawn rates, but their Mining Fatigue effect makes construction significantly harder. It's highly recommended to defeat the three Elder Guardians residing in each monument before starting major farm construction.

• Spawn Conditions:

  • Guardians require at least a 1x1x1 space occupied by a water source block to spawn. They actually need slightly more vertical space, effectively a 1x2x1 area where the bottom block is water, but the spawn check targets the single block.
  • While they can spawn at any Y-level within the monument's bounding box where water exists, spawn rates are technically higher in areas further from the edges of the bounding box and potentially influenced by water depth, though maximizing spawnable water volume is the most practical approach.
  • Guardians can spawn on any solid block surface that is submerged in a valid water source block. They can also spawn mid-water if the block beneath them is non-solid (like a sign or trapdoor) but still has a water source block at their spawn location. Understanding this helps when designing spawning platforms – you want them to spawn only where you intend them to.
  • Guardian spawn attempts occur more frequently during the daytime cycle in Minecraft. While they spawn 24/7, optimizing for daytime spawns can slightly increase rates, though most efficient farms rely on overwhelming spawn spaces rather than time-of-day mechanics.
  • Like other mobs, guardians will not spawn within a 24-block spherical radius of the player. Your AFK spot needs to be positioned carefully to keep the spawning areas outside this radius but within the 128-block despawn sphere.

Farm Types

Choosing the right farm type depends on your resource availability, technical skill, and desired output.

1. Basic Guardian Farm

This type is often built by modifying the existing monument structure rather than completely redesigning the spawning area.

Best for:

• Players needing a moderate, steady supply of prismarine for initial projects.
• Easier and faster construction, often involving minimal draining.
• Lower resource cost, requiring fewer complex Redstone components or large amounts of building blocks.

Key Components:

• Spawning platforms: Often involves clearing out sections inside the monument and relying on the natural water columns, or creating simple platforms within drained rooms. The key is channeling spawned guardians towards a central point.
• Collection system: Typically uses water streams flowing over hopper carpets or directly into hopper lines beneath a killing chamber. Simple item elevators (like bubble columns or dropper towers) might be used.
• Killing mechanism: Common methods include fall damage (dropping guardians from a significant height onto hoppers), magma blocks (causing damage while allowing items to fall through), or manual killing with a Looting sword for increased drops and XP.
• AFK spot: Usually positioned above the center of the monument, high enough to be outside the 24-block spawn-blocking radius but low enough to keep the farm active.

2. Advanced Guardian Farm

These farms aim for maximum possible spawn rates by controlling every aspect of the spawning and killing process. They often involve completely removing the monument structure and draining the entire bounding box.

Best for:

• Players requiring massive amounts of prismarine and fish for large-scale builds or trading.
• Achieving the highest possible drop rates and significant XP gain.
• Players comfortable with large-scale draining projects and potentially complex Redstone.

Key Components:

• Optimized Spawning Platforms: These farms typically involve draining the entire 58x58 area of the monument's bounding box and constructing multiple precisely designed layers of spawning platforms. These platforms often use flowing water mechanics (e.g., water sources pushed by pistons or flowing over signs/trapdoors) to quickly flush guardians off the platforms and into a central drop or transport system. Maximizing water source blocks within the bounding box is key.
• High-Speed Collection System: Often employs networks of hopper minecarts running beneath the kill zone for rapid item pickup over large areas, feeding into sophisticated item sorters and bulk storage systems (like shulker box loaders).
• Efficient Killing Mechanism: Trident killers are extremely popular for advanced farms. These use pistons to repeatedly push tridents entity, rapidly damaging mobs caught in the area. This method allows players to gain XP and Looting benefits by simply holding a Looting III sword while AFK nearby. Other options include optimized fall damage or portals linked to the Nether for killing.
• Precision AFK Spot: Placed at the exact coordinates (usually centered horizontally and at a specific Y-level) to maximize the number of active spawning platforms within the 128-block despawn sphere while staying outside the 24-block no-spawn zone. Often enclosed in a safe glass box.

Building Steps

Building a guardian farm is a multi-stage process requiring patience and preparation.

1. Preparation

• Find an ocean monument: Use ocean explorer maps obtained from cartographer villagers, or systematically explore deep ocean biomes. Look for the distinctive cyan glow of sea lanterns underwater.
• Gather materials: This is a massive undertaking. You'll need:
  • Tools: Several high-durability pickaxes (Efficiency V, Unbreaking III, Mending), shovels, axes. Silk Touch is useful for collecting sea lanterns or glass.
  • Building Blocks: Vast quantities of a chosen block for platforms and walls (cobblestone, stone bricks, glass are common). Glass is excellent for visibility. Non-spawnable blocks like bottom slabs or leaves might be needed for specific areas.
  • Water Control: Sponges are invaluable for draining sections. Sand or gravel can be used to create temporary walls for easier draining. Buckets are essential.
  • Potions/Gear: Water Breathing potions (or a Conduit/Respiration III helmet), Night Vision potions, Depth Strider III boots are almost mandatory. Feather Falling IV is highly recommended.
  • Scaffolding: Makes navigating vertically much easier and safer during construction.
  • Food: Lots of high-saturation food to sustain yourself.
• Plan farm layout: Decide whether you're building a basic or advanced farm. Sketch out the design, considering spawning platform layout, mob transport, kill chamber location, collection system flow, and the AFK spot position relative to the spawning area. Mark the corners of the monument's bounding box.
• Prepare safety measures: Before starting, defeat the three Elder Guardians to remove the Mining Fatigue effect. Set up a temporary nearby base (on the surface or underwater with air pockets) with beds, storage, and crafting facilities. Bring totems of undying if available. Be prepared to fight off guardians constantly during the initial phases.

2. Construction

This is the most labor-intensive phase. Work methodically and double-check your layout.

• Build spawning platforms:
  • Basic Farm: Clear rooms within the monument, ensuring water source blocks remain where you want spawns. Use signs or fences to guide guardians with water flows.
  • Advanced Farm: Drain the entire monument area (a massive task often involving sectioning with sand walls and extensive sponge use). Build layers of platforms at precise Y-levels within the bounding box. Common designs involve rows of blocks with water sources flowing off the edges, guided by signs or open fence gates to prevent water spillage while allowing guardians to fall through. Ensure only designated spots are valid water spawn locations within the bounding box.
• Create mob transportation: Design a system to move guardians from the spawning platforms to the killing area.
  • Water Streams: Use carefully placed water sources and signs/fences to create channels that push guardians along.
  • Bubble Columns: Soul sand creates upward bubble columns to lift guardians; magma blocks create downward columns (useful for drowning other mobs, but not guardians).
  • Gravity: The simplest method – let guardians fall directly from spawn platforms into a kill chamber below. This requires significant vertical space.
• Implement killing mechanism:
  • Fall Damage: Create a long drop (over 45 blocks usually guarantees a kill) ending on hoppers. Simple, but yields no XP.
  • Magma Blocks: A floor of magma blocks damages guardians standing on them. Place hoppers or hopper minecarts underneath to collect drops. Yields no XP.
  • Trident Killer: Build a Redstone contraption using pistons to repeatedly sweep thrown tridents through a small chamber. Guardians are pushed into this chamber. Requires Redstone knowledge but allows for XP gain and Looting enchantment benefits. Ensure the player AFKs nearby.
  • Nether Portal: Push guardians through a large portal. They can be killed manually or automatically in the Nether. This offloads lag from the Overworld.
• Add collection system: Ensure all drops are collected efficiently.
  • Hoppers: Place hoppers under the kill zone, feeding into chests or item elevators. Hopper carpets (hoppers covered by carpets) can be used in water streams.
  • Hopper Minecarts: Run rails beneath the kill floor/collection streams with hopper minecarts continuously picking up items. Excellent for large areas.
  • Water Streams/Ice: Use water streams over packed ice to quickly transport items to a central sorting and storage area.

3. Optimization

Once the basic farm is operational, focus on improving its efficiency and convenience.

• Add multiple layers: If space allows within the bounding box, constructing additional identical spawning layers vertically will significantly increase potential spawn rates, provided your transport and killing system can handle the load.
• Improve killing mechanism: Upgrade from manual or fall damage to a trident killer for XP and better drops with Looting. Optimize trident killer timing or add more pistons/tridents if needed. Ensure it handles the maximum potential mob flow without clogging.
• Enhance collection system: Implement an automatic item sorter to separate prismarine shards, crystals, raw fish (cod, salmon), and potentially ink sacs (from squid spawning nearby, not guardians). Connect this to a bulk storage system (e.g., rows of double chests, potentially linked to shulker box loaders).
• Create AFK spot: Build a safe, enclosed AFK spot (often a small glass box) at the optimal location calculated during planning. Ensure it's comfortable for long AFK sessions (e.g., include a bed nearby, but outside the farm's immediate loading zone if using Nether portals). Ensure the spot keeps the maximum number of spawning platforms within the 128-block sphere while being >24 blocks away.

Advanced Tips

Pushing your farm's performance and ensuring its longevity requires attention to detail.

Efficiency Improvements

• Use Looting III sword: Absolutely essential for maximizing shard and crystal drops. Either kill manually or hold the sword while AFKing near an active trident killer. The difference is substantial (up to +3 drops per guardian).
• Implement proper mob health management: For XP farms using trident killers, ensure the killer doesn't instantly kill guardians but leaves them with low health for the player's sweep attack (or thorns/potion effect) to finish, granting XP. Fall damage can also be precisely calculated to leave guardians at half a heart.
• Add automatic collection: Go beyond basic hoppers. Use hopper minecarts running on looped tracks under the entire kill floor/collection area, unloading into a dedicated sorting system. This prevents item buildup and potential lag/despawning. Consider using water streams flowing over packed ice for rapid item transport to the sorter.
• Create backup systems: Implement overflow protection for your storage system (e.g., items diverted to lava or trash chests when main storage is full) to prevent catastrophic backlog and lag if you AFK for extended periods.

Safety Considerations

• Build proper lighting: While guardians ignore light, other hostile mobs don't. Thoroughly light up any walkways, surrounding structures, the roof of the farm (if below skylight), and nearby ocean floor/caves to prevent unwanted spawns that could reduce guardian rates or pose a threat.
• Create safe access points: Establish secure ways to enter and exit the farm and AFK spot. Bubble elevators, secure tunnels from a nearby landmass, or Nether portal links are common solutions. Avoid entrances that require risky flights or swims near active farm components.
• Add emergency exits: Have a planned escape route from the main construction or AFK areas in case something goes wrong (e.g., trident killer malfunction, accidental flood, creeper explosion on a walkway).
• Implement fail-safes: Consider adding an easily accessible lever to disable Redstone components like trident killers or flushing mechanisms if needed for maintenance or emergencies. Ensure your AFK spot is completely enclosed and mob-proof. Always deal with the Elder Guardians before starting construction to avoid Mining Fatigue hampering your work or escape.

Remember that a well-designed guardian farm, whether basic or advanced, is a significant long-term investment in your Minecraft world. It can provide you with virtually unlimited quantities of prismarine shards, crystals, and fish, unlocking powerful game mechanics and aesthetic building palettes. Take your time, plan carefully, and enjoy the rewarding process of conquering the ocean monument!