Theater Mechanicus is a tower defense minigame that is part of the Lantern Rite event in version 1.3. To unlock this, complete the quests "The Origin of the Lanterns" and "Liyue: Theater Mechanicus". Build some towers to defend your Ley Line monolith, or to prevent the enemies from escaping to win the game. There are a total of 8 difficulty modes for different multipliers to get more currency rewards for the event's exchange shop: Xiao Market.
Event Duration
2021/02/10 10:00:00 – 2021/02/28 03:59
Event Gameplay
To start the event, talk to Ruijin in Liyue Harbor. You will need 1 Xiao lantern to attempt it each time, and will get used up regardless if you win the fight or not.
At the start of the game, players are given time, as shown at the top of the screen, to build some towers in designated locations by using veneficus points. Enemies will be coming in waves, and the paths that they take in the area are shown by a blue light coming from the purple portal. You can get more veneficus points by defeating enemies, or removing a built tower.
Enemies won't be attacking any players there, and you won't be able to deal damage to them. However, you can use elemental skills to apply an element on the enemies. These can be useful for causing reaction to help deal damage from the towers.
Mystic Arts
At the end of each waves, you will be able to choose a mystic art for the stage. These have various effects ranging from making your towers more powerful, or increase veneficus points gained. There are also stronger buffs that will come with some negatives.
Useful Characters
Geo main character can place down geo constructs that can sort of help block the road. Some enemies can easily get around it though. The elemental skill can also be used to knock smaller enemies away.
Anemo characters like Sucrose or Jean are useful for their hard crowd control abilities, which can be used to knock enemies into pitfalls. Sucrose has 2 elemental skill charges if you have her at constellation 1, and her charged attack can knock smaller enemies too, making her slightly more useful than Jean.
Shatter (Hydro + Cryo) can apparently deal damage to enemies, and Chongyun is the character of choice for this since he's Cryo and able to destroy frozen enemies because he uses claymore. You can use the towers to apply the Hydro to freeze the enemies, or bring characters like Xingqiu/Barbara.
General tips
Be sure to upgrade your towers in the armory before entering the stage. The towers have additional effects when they reach level 3 or 5.
Stages with bridges that you can turn off are very useful for getting rid of high HP enemies like ruin guards from the Mystic Arts.
Cryo towers are quite good because Cryo element slows movement speed of enemies, and it's recommended to place them a few spaces away from the starting portal because they have good range.
You can apply elements on to enemies to make the towers deal increased damage from reaction. So applying Pyro to enemies before the Cryo tower hits the enemy will cause "Melt" reaction that can one shot weaker enemies.
The line of path that the enemy takes is shown to be straightforward, so if you ever want to place a mine, then it needs to be in the middle of the lanes. Placing it one the sides won't work unless you push enemies to touch the mine.
The mine is very cheap, and a good way to deal high damage repeatedly by placing it down after it explodes.
Check the incoming enemies to see if there's a bunch of a certain element for the next wave. If there are a lot of Pyro slimes for the next wave, then you will want to remove your Pyro towers, and place more Hydro towers.
Recommended to at least bring 1 archer so you can disable ruin guards for a few seconds by hitting its weakpoint.
You can deal damage to enemies by causing "Shatter" elemental reaction by destroying enemies in frozen in ice using a claymore or Geo element attack.
Stage 1
First stage is fairly easy since both of the spawning portals are quite close, and both go down into the same stairs. You can either build some Cryo towers to start dealing damage from afar, or use Hydro towers so you can use recovery tower to get more points from kills in the circle.
There's also a gap/ravine in the middle of the stage for you to push enemies into it. It helps with dealing against some fast enemies without using any veneficus points.
Stage 2
In this stage, the two enemy spawn portals come from separate lanes. There are some spots for you to make a tower near each portal, but it's easier and more recommended to build the towers near the bridge instead. This is because there's only 1 blue portal, and enemies have to go through the bridge, as shown by the enemy path line.
The stage also has a device that you can use to turn off the bridge. There is a long cooldown between uses, and using it costs some veneficus points. Use it if you encounter enemies that are hard to deal with like Ruin Guards/Hunters/Graders like the one spawned because of mystic arts.
Building the towers in front of the bridge and behind the bridge are the easy and safe choices, but it can cause the game to last longer to complete because of the enemy travel speed and distance. As usual, start with Cryo towers to slow down their speed, then you can either use Cryo towers to freeze them when they get closer, or use Pyro to deal high Melt damage.
Stage 3
This stage definitely encourages going into multiplayer, but it's definitely not impossible to clear in solo, as long as you properly upgrade your tower levels.
The 2 enemy spawn portals are in 2 different lanes. You can glide from the upper lane to the lower one, but not the other way around unless you activate the stage device, but it's not really that useful.
Starting with the Cryo tower still works, though you might need to upgrade it to level 3 or 5 for the splash damage. To the side of the Cryo tower, placing a Hydro tower will help freeze enemies so they stay in place so they can take more damage, also buying you some time in case you need to go back and forth. If you've already unlocked the mine, you can place one down in the middle of the lanes as a failsafe.
It's important to keep in mind that if you get the stage again on a different attempt, that the portal's location can be reversed. Just make sure to check which one is the purple one, and which one is the blue, or you can look at the enemy path line direction to see where they are coming from.
Stage 4
This stage has 2 enemy spawn portals, but they are on a different side, and the one in front splits into 2 different paths. This can be difficult to manage at first, but the important thing is to place the towers close to where they need to go, which is the 2 blue portals on the side.
Place some Cryo towers near the bridge as shown in the picture above, and they can shoot enemies coming from the north and south. You can then either put Pyro tower to deal massive damage at a slower pace, or use Hydro tower to freeze enemies near it to stop enemies from the north.
On the sides, you will need to place down some towers as well. At the start of the stage, with only limited veneficus points, you can go with just placing some mines instead because they're cheap. Place down some towers after you get more and more points as the stage progresses.
Stage 5
In this stage, enemies are coming from 3 different portals, and they can be somewhat difficult to manage in solo. However, there is only 1 blue portal, so all enemies will eventually go to the same place. You can essentially focus your resources on placing towers near the blue portal for convenience.
This is an easy starting setup to use. 2 Cryo towers in the front, and 2 Hydro towers behind it, with a mine in the middle in case enemies break through, and can be easily replaced once it gets used.
Once the third portal on the side opens up, you will want to place more towers near the stairs to help defeat those incoming monsters, because the one in the bridge won't be enough.
this map also has a stage interactive device on the sides, but it's only to create some wind to help get between lanes easier.
Co-Op Notes
This event challenge can be done in co-op, but there are small differences between doing it in multiplayer and solo:
Veneficus Points and tower upgrades are stored individually, instead of using a shared resource.
The max constructible tower is a collective limit that is shared between all players
Leaving the challenge before it's completed will give both players a penalty that prevents them from joining another co-op session for a set amount of time.
Stages and Scoring System
There are a total of 6 stages, and you unlock them one at a time after completing the previous stage. You can attempt to do each stage at a certain difficulty level. The higher the level, the higher the reward multiplier.
The amount of points that you get is based on the challenges that you complete, multiplied by the difficulty multiplier.
Rewards
Completing the event rewards you with veneficus sigils, which is used to unlock or upgrade your towers.
Completing the event challenges gives you Peace Talismans, which is the currency needed to buy things at the exchange shop.
Among the available rewards in the event, you can spend 1,000 Peace Talismans in "Stand by Me" to invite one of Liyue's 4-star character to join your Party.