Tutorials Monster spawner traps


Info

Finding dungeons

Dungeons are found when tunneling or exploring caves and abandoned mineshafts Abandoned mineshaft Biome Any Consists of Wooden Planks Fence Rail Torch Cobweb Dirt Monster Spawner Minecart with Chest Can generate post-generation No First appearances See history "Mine" redirects here. For information about mining, see Mining. minecraft . They appear to spawn in random places, but almost always underground, usually at the Y=30 to Y=60 range. Finding dungeons without mods, cheats, or external programs is mostly attributed to luck and some know how. While exploring, some tricks can be used to help detect dungeons. Gravity blocks like sand and gravel in a neat square is typically covering a spawner, and is very visible in deserts if spawned near the surface. Listening or seeing a group of single-type mobs while caving could mean a spawner is nearby. Lastly, naturally spawning cobblestone and mossy cobblestone not near lava and walled is a dungeon, unless it is in a jungle A river bisecting a jungle biome. At the top right is a forest. A river running through a mesa biome with mesa plateaus, with a savanna biome in the bottom right. “ In case you minecraft biome, where it can also be a jungle temple Jungle Temple Biome Jungle Consists of See Blocks Can generate post-generation No First appearances See History Jungle temples are generated structures found in jungle biomes. Contents 1 Generation 2 Structure 2.1 Puzzle 2.2 Trap 2.3 minecraft .

Mob spawners can be neutralized by placing torches to light up any dark areas around the spawner. Be that as it may, because blazes can spawn in light level 11 or below, torches (light level 14) are not very effective for neutralizing blaze spawners. There are six types of mobs that can spawn (7 if you count the zombie pigman, but they spawn from nether portals not the actual monster spawner block). They are separated into a couple categories: the two block high tall mobs and the one block high short mobs. The Tall Mobs are zombies, skeletons and blazes, while the Short Mobs are the two varieties of spiders and silverfish.

In the Nether A view of the Nether. The Nether is a hell-like dimension, filled with fire, lava, and dangerous mobs. Contents 1 Accessing 2 Environment 2.1 Mobs 3 Generation 3.1 Naturally generated 3.2 Naturally created 3.3 Structures minecraft , blaze Blaze Health points 20 () Attack strength Fireball: 5 () Contact: Easy: 4 () Normal: 6 () Hard: 9 () Size Height: 1.8 Blocks Width: 0.6 Blocks Spawn Nether Fortresses, light level of 11 or minecraft spawners can be generated in nether fortresses Nether Fortress Biome The Nether Consists of See Structure First appearances See history Nether fortresses are structures that are naturally generated in the Nether. Contents 1 Generation 1.1 Mobs 2 Structure 2.1 Blocks 3 Loot minecraft , and can be trapped to collect blaze rods Blaze Rod Type Items Durability N/A Renewable Yes Stackable Yes (64) First appearances See history Data value dec: 369 hex: 171 bin: 101110001 Name blaze_rod Blaze rods are items that are dropped by blazes. Contents 1 Obtaining 1.1 minecraft and mass amounts of experience. Blaze spawners are the most dangerous to trap because of the height of the structure and the additional danger of lava. One must be well-prepared to contain this type of spawner, lest they might die from heights, lava, the blazes, or even external mobs.

Silverfish Silverfish Health points 8 () Attack strength 1 () Size Height: 0.3 Blocks Width: 0.4 Blocks Spawn After mining monster eggs or from spawners in strongholds. First appearances See History Drops None Experience 5 Sounds minecraft spawners can be found in the portal room of a stronghold Stronghold Portal Room Biome Any Consists of See Structure First appearances See History Strongholds are structures that occur naturally underground, and are primarily important because they house end portals. Strongholds can be located using eyes minecraft . Be that as it may, silverfish do not drop anything and are bothersome unless properly trapped. You may choose to simply break the spawner, unless you want to create a silverfish trap near an entrance to your base. Silverfish do have some advantages, as they are the easiest hostile mob to kill and produce an average amount of experience.

Normal spider spawners are one of the easiest to trap, as they can not fit through a 1 wide hole, so you can dig through the side and place a torch on the spawner without fear of getting hurt.

Cave spider spawners are hard to trap, and since you will get poisoned "Healing" redirects here. For health, see health. Contents 1 Behavior 2 Summary of effects 3 List of effects 3.1 Absorption 3.2 Bad Luck 3.3 Blindness 3.4 Fire Resistance 3.5 Glowing 3.6 Haste 3.7 Health Boost minecraft on normal or higher difficulty, novice and intermediate players may be better off breaking these as soon as possible. These spawners are generated far more often than other types, and some may even generate within 20 blocks of another, which can be made into a very efficient trap. Being very small mobs, they can fit through 1ℂₗ1 spaces, and even between half-slabs, which makes for a mixed blessing. On the one hand, extremely small, simple, and efficient grinders can be made, but on the other hand, they`re far more difficult to contain, potentially leading to spiders leaking out and/or fatally poisoning the players.

Zombie spawners are also a bit tricky, as the spawner may spawn baby zombies, which are a 1ℂₗ1 mob, making proper containment essential, (and particularly on harder difficulties), the zombies may spawn other zombies nearby to "help", making area security a priority or problematic, and the Spawner may also spawn zombie villagers Zombie Health points 20 () Armor points 2 () Attack strength Easy: 2 () Normal: 3 () Hard: 4 () Size Adult: Height: 1.95 Blocks Width: 0.6 Blocks Baby: Height: 0.975 Blocks Width: 0.3 Blocks Spawn minecraft which makes adding in some manner of player controlled sorting mechanism a consideration. On that note, be that as it may, zombie spawners can prove to be one of the most lucrative to trap, as the variety of items it can drop is extensive, and potentially limitless if you factor in the added option to use it to generate Villagers, which can then in turn be traded with, themselves "farmed", or used to make iron golem Iron Golem Health points 100 ( × 50) Attack strength 7 () to 21 ( × 10.5) To players: Easy: 4 () to 11 () Normal: 7 () to 21 ( × 10.5) Hard: 10 minecraft farms.

Videos

Simple farms

The three most common types of spawner are for zombies, skeletons, and spiders Spider Health points 16 () Attack strength Easy: 2 () Normal: 2 () Hard: 3 () Size Height: 0.9 Blocks Width: 1.4 Blocks Spawn Light level of 7 or less, 3×3×2 space on solid blocks minecraft . In each case, it`s fairly trivial to set them up so that you can attack the monsters without retaliation, forming a simple farm for XP and their drops. (Sometimes cave spider Cave Spider Health points 12 () Attack strength Easy: 2 () Normal: 2 () Hard: 3 () Venom: 1 () per 1.25 sec Hard: for 15 sec () Normal: for 7 sec () Size Height: minecraft spawners can be treated similarly, but this is more hazardous.) Proceed as follows:

  • Secure and light the area around the dungeon! Light the room and spawner while you work on it, so the monsters don`t interrupt you.
  • Ransack and clear out the chests. Choose and prepare a "front" area for the farm, with a chest and crafting table to supply stone swords for cheap slaughter. Make sure you have a clear approach and/or room to back away quickly, in case you come by and find one or more creepers spawned inside, and you need to shoot them.
  • Prepare the spawner area, and especially, open up the entire spawning range: Horizontally, that`s 9x9, centered the spawner. That range also includes a block above and below the spawner, so take up the original cobblestone and moss-stone floor, if necessary supplying a new floor one level below. Extend the front to match, so you don`t have monsters or items hiding in corners.
  • Now seal off extra exits and alcoves, fill stray holes, and place fences or other barriers to channel mobs toward the front. If you want any redstone circuits, now is the time to set up the alcoves and access tunnels.
  • Optionally, set up redstone systems:
  • Prepare the front according to the monster type. You will always want fence gates, in case you want to dash in between spawns to collect drops, or to fix something up.
    • For zombies, a simple gated fence will do. Maximize your view of the spawner, so that they come to the fence quickly.
    • For spiders, you want one or more 1-block wide slits, 2 or 3 blocks high. You can attack them, they can`t come through. To defend against creepers and other non-spider spawns, you can make these slits two-high, between top and bottom slabs. (That is, three blocks total, but with the top and bottom spaces half-blocked by slabs.) The "tall" monsters will not recognize these as passable, but you can move or attack through them easily.
    • For cave spiders (if you must), you can place a door between floor-to-ceiling fences (see pictures below). Iron doors are better, so that you can`t accidentally open it while you`re whacking at the spiders.
      • Note that cave spider spawners don`t come pre-enclosed in a dungeon, so you`ll likely need to start by building a room around them. Remember that the spiders can appear up to 4 blocks away (depending on direction) from the spawner, whether or not there`s a wall in the way.
    • Skeletons are trickiest: They can shoot through even brief gaps, the moment they get the angle. For the actual killing zone, you want fences/gates at eye level (so they can`t shoot you), with an open row below (so you can attack). If you stand directly in front of the fence, they will usually come up to the front so you can attack them. That row in front of the fence can also be a trench⃢₀ₔyou can reach further into the room, but then they will occasionally get an arrow or two under the fences.
  • Once your farm is prepared, remove most or all of the lights. Beat a hasty retreat to the front.
    • Special case: If you found a dungeon in a mushroom biome, congratulations! Since creepers can`t spawn, you can pull out all the lights in the dungeon room, and get maximum output from the spawner.
  • Make some stone swords and whack away. Keep bow and arrows handy near the entrance, in case a creeper spawns while you`re away or approaching, or otherwise sneak into the room. (Normal darkness spawns are suppressed within 24 blocks of a player.) It is also possible to kill creepers by hitting them, backing off, and repeating. With an iron sword you can just rush a creeper and kill it before it explodes.

Killing mechanism

Any standard mob grinder Mob grinders are the last part of a mob farm and are used to kill mobs in massive amounts while also collecting all dropped items at a convenient location. They are a mechanism and can minecraft can be connected to a dungeon. Be that as it may, the purpose of this device is for players who are currently low on materials and can`t yet build something larger See farms which spawn mobs in natural conditions. For single-species farms built around a Monster Spawner, see Tutorials/Monster Spawner Traps. Mob Farms are structures built to acquire mob drops more easily and minecraft . As of version 1.5, a hopper Hopper Type Block Entity Physics No Transparency Partial (does not block light, mob spawning possible) Luminance No Blast resistance 24 Hardness 3 Tool Renewable Yes Stackable Yes (64) Flammable No First appearances See History Drops minecraft can be used to collect the items into a chest.

Lava blade traps

A lava blade trap consists of using water Water Transparency Partial (-2 to light) Luminance No Blast resistance 500 (Flowing) 500 (Still) Tool Renewable Yes Stackable N/A Flammable No Drops None Data values Flowing Water dec: 08 hex: 8 bin: 1000 Still Water dec: 09 hex: 9 bin: 1001 minecraft underneath the spawner and funneling these into a single line. At this point the mob should find themselves approaching a sign at ground level and a `lava blade` above it which flows over the top of the sign Sign Type Non-Solid Block Physics No Transparency Yes Luminance No Blast resistance 5 Hardness 1 Tool Renewable Yes Stackable Yes (16) Flammable No, but catches fire from lava (Yes in Pocket Edition) First appearances See minecraft but no further. This allows the mob to drop items at their feet for your collection. A tutorial can be found here.

Drowning traps

Drowning traps employ water Water Transparency Partial (-2 to light) Luminance No Blast resistance 500 (Flowing) 500 (Still) Tool Renewable Yes Stackable N/A Flammable No Drops None Data values Flowing Water dec: 08 hex: 8 bin: 1000 Still Water dec: 09 hex: 9 bin: 1001 minecraft to drown the hostile mobs. Mobs float in water and items drop, which allows easy separation. In this example, the dungeon is a 5ℂₗ5 zombie spawner.

Take out the torches and enclose the dungeon. This was designed for tall mobs, but can be modified for spiders by making the drowning chamber larger. Use signs to hold up water.

Please note that the below tutorial is slightly imperfect; the glass panes have air spaces, sometimes letting the mobs survive. Use glass blocks instead, to prevent this.

Please note that this video shows the incorrect process. You must fill up the column using source blocks, not just one at the top.

Flow trap

This trap is highly recommended. It`s effective and safe on all mobs, except blazes, since you need water. Disable the spawner, and then make an 10ℂₗ10 room around the spawner. On one side, place water on every other block. On the opposite side, make a one block deep trench extending along the side opposite the water. Light up the trench well. If you want, you can add a pool for fish and get a fishing rod to fish. Then, make a wall with a line of air at eye level to look through and strike. The holes have to be next to water. Now, get plenty of food, a few chests, and two or three swords. Now, remove the torches and let mobs spawn. The water will bring them and the drops to you, and you can shoot them and hit them. Also, make a room to eat and heal in safety, just in case you didn`t build the trap thoroughly. With this trap, You can go for hours in one go, and gain hundreds of experience levels and items at minimum risk. The trap system is built in a way where you can easily leave when you want, with almost no creepers or non-spawner mobs popping up.

  • If the spawner is a spider, make these adjustments:
    • Add iron doors with levers to control mob flooding and possible death.
    • Bring milk.
      • This precaution is for cave spiders.
    • Add an on/off lighting system.
    • Bring bows to help control mob flooding and possible death.

Sunlight based traps

This type only applies to zombie Zombie Health points 20 () Armor points 2 () Attack strength Easy: 2 () Normal: 3 () Hard: 4 () Size Adult: Height: 1.95 Blocks Width: 0.6 Blocks Baby: Height: 0.975 Blocks Width: 0.3 Blocks Spawn minecraft and skeleton Skeleton Health points 20 () Attack strength Bow: Easy: 1 () - 4 () Normal: 1 () - 4 () Hard: 1 () - 5 () Sword: Easy: 2 () Normal: 2 () Hard: 3 minecraft mob spawners. Sunlight based traps are made by placing water below a spawner. This water will flow from one side to another. Where the water stops, dig a pit a few levels down. This will drop the mobs into the pit. To finish, make sure that the pit is open to sunlight. This sunlight will burn the mobs alive. An example of this can be found here.

Potion-based trap

This is a fairly expensive and hard to make trap, so it`s not recommended.

First: Light up the room to prevent mobs from spawning.

Second: On top, dig out 2 blocks from the spawner room top without breaking the spawner roof

Third: Place the wires and dispensers like shown:

 DWWWWWD    X - Roof Block XXXWXXX    W - Wires XXXWXXX    D - Dispenser looking in the spawner room XXXLXXX    L - Lever, button or even a redstone clock, whatever you want to power   XXXWXXX        the dispensers up! XXXWXXX DWWWWWD  

Fourth: Put inside the dispensers:

HARMING POTIONS: Used to damage spiders. HEALING POTIONS: Used to damage skeletons and zombies. POISON POTIONS: Used to weaken any mob that is not undead.

Fifth and last, but not least: Take the lights out, get up, and when you hear the roars, push the lever/activate clock/ whatever you used to power it up.

Again, it`s expensive, so it`s a lot better to use water or lava traps until you got a blaze trap, a lot of patience and potions, or just playing Creative/Having TooManyItems, or you can use witch to let witch throw potions to the trap filled with mobs, but it`ll despawn if you`re going too far away from them, and witches don`t throw healing potions, so it`s only usable for any mob that is not undead.

Iron golem traps

In this trap an iron golem Iron Golem Health points 100 ( × 50) Attack strength 7 () to 21 ( × 10.5) To players: Easy: 4 () to 11 () Normal: 7 () to 21 ( × 10.5) Hard: 10 minecraft is used to kill the monsters for you. To make it, simply make an iron golem in the dungeon and watch it kill for you. Be that as it may, the iron golem will eventually die (especially if more than 1 enemy is spawned), so you`ll have to replace it with another, or link it to an iron golem farm An Iron Golem farm is an easy way to acquire many iron ingots (and less useful poppies) with minimal effort after the initial setup. It is an artificial village (or several of them, spaced far minecraft .

Cactus traps

The following cactus trap is designed for spiders. It has a chance of destroying the items, but this is an inherent issue with cacti. (This can also incorporate a small cactus farm by placing a block 2 blocks above the cacti.)

  • Dig the main channel. The spider spawner is left in the wall forcing spiders to spawn on the small dry patch.
  • Dig two blocks down and one block in just before the cacti. These two holes will hold the collection water sources.
  • Place three ladders on the far side of the collection output. Place one on either piece of sand. Place the two water sources in the holes.
  • Place the main water in the two openings. The block between them makes the water flow towards the gap in the cacti, slightly improving the collection rate of string.
  • Cover the entire trap and remove all lights.

Villager traps

  • First make a room high above the ground and move at least 2 villagers to it.
  • Now put at least nine doors in it.
  • Next change one of the one wall in the room to glass.
  • Attach another room to the side that the glass wall is on.
  • Mine a hole in the floor of the empty room.
  • Line the hole with open trap doors (if your hole is 2 by 2 you will need 4 trap doors)
  • Directly under the hole, make a room without a roof on the ground.
  • This trap only works with zombies
  • Both rooms that are in the sky must be very dark
  • The zombies will try to get the villagers, they will fall through the hole, and if the room was high enough kill themselves in doing so and drop some awesome stuff!

Blaze traps

Since it is impossible to obtain water in the Nether A view of the Nether. The Nether is a hell-like dimension, filled with fire, lava, and dangerous mobs. Contents 1 Accessing 2 Environment 2.1 Mobs 3 Generation 3.1 Naturally generated 3.2 Naturally created 3.3 Structures minecraft for a drowning trap, this trap takes advantage of blazes` weakness to snowballs Snowball Type Combat Durability N/A Renewable Yes Stackable Yes (16) Internal ID PC: 11 PE: 81 Network ID PC: 61 Entity ID snowball First appearances See History Data value dec: 332 hex: 14C bin: 101001100 Name snowball Snowballs minecraft . To create this trap, one must disable the blaze spawner and fence a snow golem Snow Golem Health points 4 () Attack strength 0 () (only pushes mobs back) 3 () to Blaze Size Height: 1.9 Blocks Width: 0.7 Blocks Spawn Where created by the player First appearances See History minecraft into a nook in a wall. Once the spawner is re-enabled, the snow golem will shoot snowballs at the blaze until it dies. Alternately, one may create a redstone mechanism that brings out glowstone Glowstone Transparency Yes Luminance 15 Blast resistance 1.5 Tool Any tool Renewable Yes Stackable Yes (64) Flammable No Drops Glowstone Dust (2–4) Data value dec: 89 hex: 59 bin: 1011001 Name glowstone See the block. minecraft or turns on redstone lights to prevent the blazes from spawning until the mechanism is switched. Fenced access to a snow golem`s nook can allow the player to construct a new one should the blaze defeat it. Be that as it may, in Minecraft version 1.2, Snow Golems die in the Nether, making this trap need a splash potion of fire resistance.

Another way to make a blaze farm is to box in the spawner so that the blazes can`t fly away. leave a space at the blazes foot level and stand so that your eye level is at that space. That way the blazes can`t hit you (mostly) but you can hit them. This is also a pretty good experience farm since each blaze is worth 10 xp. Be warned however that sometimes blazes will spawn outside the box so it is advised that one box themselves in as well.

(Patched) Be that as it may, if you are playing on the Xbox 360 edition (This no longer works due to recent updates.), you can make a MUCH easier trap using ice, cobblestone/nether brick, and light sources. First, make an 8ℂₗ8ℂₗ3 space around the spawner (recommended you do this on peaceful and creative as you could be killed by blazes, fall in lava, or the spawner may be destroyed by ghast fireballs, as well as ice not being available in survival). This will require destroying the fences around the spawner. Next, place ice in a row along the back of the trap and place a light source above it (recommended glowstone) so that the ice will melt. Once the ice melts, you can destroy the light source above it. Repeat this step until you get flowing water to the front of the trap. Afterwards make a place where you will sit and wait for the blazes to spawn so you can kill them (The water alone will kill them, but you will not get any loot or xp.) Make a hole as wide as the trap`s insides and one block high. If you let water flow into the area, you will not catch on fire if you are hit by a fireball (though you will take impact damage), at the cost of being faster to get to the loot, so make a platform out of the water to move around. Then, get your Looting sword (preferably diamond with Sharpness and no Knockback, as Knockback will send the blaze into still water caused by the ice, which will keep it from flowing toward you) and beat the blaze rods and glowstone dust out of them!

Alternatively, see 1

A note on lava

Lava can quickly kill mobs and can be suspended on either a ladder or a sign. To suspend the lava, create a 3-long channel then put a sign or ladder on the last block. Lava spreads three blocks away from the source, so the last section of the lava will be left suspended on the sign or ladder.

Lava generates light, which can lower the spawn rate in the dungeon unless placed far away; however the increased turnover of mobs may compensate for this. (Only one trial - lava `blade` is approximately 7 blocks away from spawner. Significantly increased rate with lava closer as opposed to having a dark spawn room with lava further away.)

Here is a video example of how to make a dungeon trap using a lava grinder in 1.2.5.

$$$@@@$$$Johnny$$$@@@$$$ Vindicator Trap

Since 1.11, you can use an Anvil, Name Tag and a Vindicator to make a Monster spawner trap. First, you need to find a Spawner, then you need to make a wall with a door to make no monsters to leave the trap, then lure a vindicator to inside the trap.

Then you go to your anvil and rename the Name Tag to "Johnny", then Right Click the Vindicator with the Name Tag (Note: It`s recommended to kill all the mobs so no mobs will kill the vindicator), After renamed, the Vindicator will attack any other mob except other Vindicators and Evokers.

It`s recommended to put more Vindicators inside the Trap. and also it`s recommended to heal your vindicator using Potions of Healing.

Auto meat cooking trap

This is when you have peaceful mobs spawn and are burned to death which cooks the dropped meat. First you cause peaceful animal mobs to spawn. Then you cause them to fall into lava that is one block high with a sign below it. This prevents the lava from flowing. Below the signs you put a block of cobweb. This causes mobs that have been caught on fire by the fire to burn and die without losing the drops. Just have a way to collect the fallen meat, and you have an Auto Meat Cooker. You can also make a chicken trap by making a big pit of fire and then go high up and put a spawner. The chickens will fall into the fire and drop cooked chicken.

A working Auto-Pork Cooker

Other

Traps that use unusual methods, such as huge pits, fall into this category.

Note: Using a half slab of cobble, planks, or sandstone in murder holes will prevent creepers and skeletons from seeing you, then you can retrieve items without breaking blocks, place the half slab on top of where the mobs would usually stand.

Pit trap

For this method, you must dig a pit that reaches far under the dungeon. Depending on the height (at least 23 blocks), the mob "Monster" redirects here. For the mob called "monster" in the code, see Human. Mobs are living, moving game entities. The term "mob" is short for "mobile". 1] Contents 1 Spawning 2 Behavior 3 List of minecraft will die on impact, as long as there aren`t any blocks of water at the bottom. Be that as it may, this method takes a long time to make and only works for spawners near or above the surface. Alternatively, you can build an elevator for the mobs using alternating water and signs to bring the mobs 23 or more blocks higher Here are some ideas for some Elevators. Contents 1 What is an elevator? 2 Piston Elevator 2.1 Extremely Fast 2.1.1 Trans-location 2.1.2 TNT Cannon 2.2 Multi-floor elevator 2.3 Up and down 2.4 Fast 2.4.1 Zipper minecraft , and then drop them 23 or more blocks in order to kill them (or you can do 22 blocks if being used for an XP farm).

Experience trap

For this trap, you need to dig a large pit 22 blocks deep under the dungeon, or make a water elevator taking them upwards so you can stay near the monster spawner. Go to the bottom of the pit and place water in a fashion so that it should flow towards a wall. Then make a room where the water is flowing. This is where you will stay while finishing off the mobs. Make the room so that it has a one-block hole where you can see the mob drop zone. Hopefully, mobs should spawn, fall down the pit and survive with half a heart, get pushed towards you by the water current, and get killed by a single hit. If you like, you can bring food along as your hunger will deplete over time. This should provide normal as well as rare mob drops and experience levels, making it quite useful. Another technique is to leave your player by the dungeon for a couple of hours, overnight is suggested, and there will be at least a hundred monsters waiting to be harvested. There is a possibility of the number of monsters causing large lag spikes, glitches, and maybe even crashing on weaker computers.

Efficient pit + experience trap w/ TuT (by Epiiik)

MC Farm.jpg
*Note, all dimensions are given the format: Horizontal x Vertical. This method is an indirect hybrid of the aforementioned traps, utilizing both fall damage and mob control with water. In the mob spawning room, dig 1 block down so that the spawner is at eye level, and place water blocks at two adjacent corners. On the wall opposite of the two water blocks, dig a 1⃗2 hole for three blocks in the middle of the wall (allowing mobs to pass through).
Begin digging upwards in a 1⃗2 fashion for 24 blocks. To get up, place signs on the long-faced wall (your left/right) in a zig-zag pattern going up while placing water blocks in between the signs. The first sign should be placed as furthest, lowest space possible. Stop placing signs after the 23rd level. The last water block should be against the wall furthest away from the mob spawner on the 24th level.
On the 25-24 block levels, dig a 1⃗2 hole for seven blocks in the direction the mob spawner. On the seventh block in, dig one block downwards. Dig in the forward direction for eight more blocks (again, 1⃗2). You should notice the water block placed on the 24th level should stop where the path drops by one block. Place a water block against the wall of the drop. Notice how this water block stops 1 block short of the path.
Dig further for two block and begin to dig downwards in a 1⃗1 fashion for 22 blocks, Face the direction of the mob spawner and dig another 1⃗2 hole one block deep. Dig down one and fill the top level with one block so that you can only see through one block of the pit you just created. (If you are using a skeleton spawner, you will need to stand one block away from this hole so that the skeletons cannot shoot you.) You are now standing at the loot point. Now that the almost-dead mobs are depositing into your 1⃗1 hole, simply attack them with any item to gain their loot and experience! You may use TNT + water to do splash damage to kill all mobs at once at the risk of lag spikes. Splash potions of Healing will also work, as they do damage to most hostile mobs.

note: you must have 2 block tall non-exploding mobs to do this or the mob will either destroy or get out of the trap

Useful tips on this design by Duck//Marvin: When you make the opening in the spawn chamber for the mobs to exit, make it 3 blocks high and place a sign or half slab at the top. This lets the mobs into the elevator more easily and prevents water spillage from the elevator. Also making the transport corridors at the top 3 blocks tall instead of 2 allows the mobs to be transported faster as they will not hit the ceiling when they try to swim and get stuck.

Lowfootprintmonstertrapexp.png

Alternative layout 1

As you can see in the picture above, there are 2 spawning rooms for the hostile mobs to spawn. This is very useful if you can silk-touch mine mob spawners. Anyhow, the dimensions for the room are 5 across, 13 down, and 9 long. The picture is slightly deceiving, because you can`t see behind the wood. To construct the spawning room(s), you will need a very durable pickaxe, or several pickaxes. You shall dig out the full room, and make a redstone lighting system to control when the mobs can and cannot spawn. You will then make a 2ℂₗ7 water elevator, bringing the mobs up 5 levels above where you will hit them. You shall then make a 1ℂₗ2 area to hit the mobs, and if room allows, a spot where water may flow to bring mob drops to you. You will be able to pick up most mob drops without this, but there are still few you won`t be able to.

Alternative layout 2

An alternative layout with a smaller footprint takes advantage of the fact that a player must be within 16 blocks of a spawner for it to activate, but that spawners only check 9 blocks vertically for spawned mobs. Build the trap as above, except instead of being off to the side, the killing floor is 4-16 squares directly above the monster spawner. This requires less materials, less x,z space and less precision in construction, though is 3-15 blocks taller.
To construct the trap this way, build a 9ℂₗ5ℂₗ9 room around the monster spawner with flowing water leading the mobs into a corner. Build a water ladder in this corner going 26-38 blocks upwards as measured from the top of the monster spawner. At the top of the ladder, direct the mobs a couple blocks in any direction with water, and into a 22 block drop chute. At the bottom of the drop chute, create a platform 1 block lower, with a 1x1