I choose a lazy person to do a hard job. Because a lazy person will find an easy way to do it. -Bill Gates
There are two things you should know about me. One: I play a lot of Terraria (and still do), both vanilla and modded. Two: I am incredibly lazy in certain situations. Luckily for us both of these can synergize.
The Lunar Events of Terraria are some of the most chaotic and literally world-changing events that any Terraria player will encounter. Not only do much of their occurrence lie outside the player's control, but they also effectively cordon off several parts of the Terraria world, preventing the player from comfortably accessing or traversing those areas. And lastly, the cordoning objects are massive boss-like Pillars, that rapidly spawn enemies at your location and must be destroyed to cleanse that part of your world. But at the same time, the pillars also drop Celestial Fragments, used to create some of the most powerful equipment in the middle or late game.
Now, while most people might fly on their Cute Fishrons or UFOs and take on the threats themselves, some take the alternative of constructing sophisticated farms to automatically confine, destroy, and collect the remains. We are not doing that here. Instead, we create a system that allows the player to do three things: 1) Efficiently reach the dungeon and pillar locations with minimal effort, 2) Defeat the Lunatic Cultist and the four pillars with minimal effort, as well as allow the player to collect the drops with minimal effort, and 3) Allow the player to defeat the Moon Lord with minimal movement. The key words here are movement and effort. Time, you will see, is something completely disregarded. This is not a guide to make a farm that will allow you to kill these things as fast as possible, but rather a trade-off between preparation effort and usage effort. It is something I build in every Terraria world and has served me well.
Before we do that, however, we must discuss the nature of the events themselves. The dungeon is easy to find, and easy to reach. The four pillars, however, do not have any marked locations on the map. Instead, they (on average) partition the world into even fifths. Terraria's system of measurement assumes one block is two feet. From the center, denoted 0, you can go some number of feet west or east to the edge. Denote this number as R, the world's radius in feet. The world's effective size (diameter) in blocks, is thus this same number R, the radius in feet, and the world's size in feet, is thus 2R.
The locations of the pillars are approximated by partitioning the world into fifths. So from the left edge of the world, the first pillar is 2R/5 feet to the east, then the next pillar would be 4R/5 feet east, and so on. The center of the world is R feet east of the west edge, so a simple coordinate offset shows that the pillar centers are +/- R/5 and +/- 3R/5 feet west/east from the world's center. Now for actual numbers. A small world is 8400 feet (4200 blocks) in diameter, so the pillar centers are [+/- 840, +/- 2520] feet. A medium world is 12800 feet (6400 blocks) in diameter, so its pillar centers are [+/- 1280, +/- 3840] feet. And a large world is 16800 feet (8400 blocks) in diameter, so its pillar centers are [+/- 1680, +/-5040] feet, twice the scale of a small world. For mods that add custom world sizes, the computations are analogous.
The first thing to do in this project is to construct a network of teleporters. Depending on your needs, you will need at least 5 teleporters (in most cases 6 will do). If there are N teleporters, your linked list would need 2(N - 1) levers/switches, enabling you to hop back and forth across the network. One to locate at your base, four to find the pillar locations, and possibly another for the dungeon. Sometimes one of the pillar locations will line up with the dungeon or something else and you can save a teleporter. You will also need an ice wand, copious amounts of wire, The Grand Design, a GPS, and at least three building blocks for each teleporter.
Place a teleporter at your base, and two levers on the edge blocks of the 3x1 top surface. Draw two wires from the levers down into the teleporter. Then, find the direction away from the dungeon (west/east), hold down the place wire button and traverse the terrain or air in that direction to the closest pillar center. The wire should go from your base to near that location. Then, locate the exact block that corresponds to the pillar center, and use an ice wand to scaffold and construct a 3x1 rectangle of building blocks centered on that horizontal position. Make sure it is a bit off the ground. Place a teleporter on it, two switches, and connect the wires so that flicking the lever in a direction takes you in that direction (e.g. from your base, flicking the left lever takes you to the -R/5 feet location, and from that center, flicking the right lever takes you back to your base).
From that teleporter, find the unused lever, and connect wire from it to the teleporter, then repeat this flying action to the +/- 3R/5 feet location, and construct another teleporter centered on exactly +/- 3R/5 feet. Finally, connect this other teleporter back to the +/- R/5 feet teleporter using levers. You only need one lever for this edge teleporter since there is no teleporter further from it. The next thing to do is to repeat the process on the other side, except this time you might want to add another teleporter for the dungeon. That side will have three teleporters: two for the pillar centers and possibly one for the dungeon. Connect them using the wires and levers the same way using the linked list technique we did earlier. Congratulations! You now have a system to efficiently bring you to the pillars and the dungeon. Now, you can theoretically proceed the same way you do normally, and fight the bosses as usual, except this time you have a convenient little system to take you directly into the pillar zones. In the next article, we will build the rest of the system and see how we can minimize the effort required to actually defeat the pillars. (Oh, also a little sidenote: monoliths are the best usage of Fragments if you wish to sell them. You will need a lot of money to build the rest of this.)