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Mission Impossible: Expert Mode Automated Playthrough (AFK from Pre-Hardmode to Moon Lord)

DicemanX

Brain of Cthulhu
It's time to close out the year with a bang with my biggest and most ambitious project to date: a fully automated playthrough from pre-hardmode all the way to the Moon Lord! In other words, I beat the game with a starting character, with only 100 life and a measly Copper Shortsword in hand, without touching the keyboard or mouse except for a bit at the beginning and one unavoidable mouse button press midway. Here are the rules I followed for this considerable challenge:


Rules for Automated Playthrough:

1) The player character must be newly created
2) The world must be in pre-hardmode with no bosses or events completed
3) The player character can be outfitted with pre-hardmode gear at the start so long as the gear doesn't require beating a boss

In the video I begin by equipping a Platinum Armor set and a Warding Obsidian Skull to reach 25 defense, the minimum necessary for the damage prevention machines used throughout the run. I then immediately teleport to the dungeon entrance and activate the Old Man's curse, and at that point the run becomes automated. Midway through the run I click the left mouse button to summon the Golem - clicking the altar is unavoidable. Everything else is completely AFK!



Video:



Playthrough Progression:


Below are the necessary (and a few optional) steps to progress from pre-hardmode all the way to the end of the game. The total playtime has so far ranged between 5 and 7 hours, the bulk of which involved waiting for the three mechanical bosses to spawn. Here are the steps:

Defeat Skeletron (necessary for Cultists to spawn at the end)
Defeat the Wall of Flesh (necessary to be able to break a Demon Altar)
Blow up all the Shadow Orbs (to trigger a meteor) and a Beehive Larva (optional)
Defeat Eater of Worlds and Queen Bee (optional)
Wait until a meteor hits at least one Demon Altar (to allow mech bosses to spawn)
Beat The Twins, The Destroyer, and Skeletron Prime (necessary to spawn Plantera Bulb)
Break a Plantera Bulb and beat Plantera (necessary to be able to summon Golem)
Farm for a Power Cell in the temple and summon and defeat The Golem (this will spawn the Cultists)
Kill the Cultists at the dungeon entrance to initiate the Lunar Event and summon the Lunatic Cultist
Defeat the Lunatic Cultist
Defeat the 4 Lunar Pillars
Defeat the Moon Lord



Notes:

This engineered world seems foolproof after much testing except for one part: the Moon Lord can kill the player when it spawns in if the player gets a very unfavorable spawn. The Moon Lord can release an eye so that it positions itself over a player teleporter, and it will kill the player (200+ damage) when the player eventually uses that teleporter. The chances of this happening are fortunately very small. Nothing can be done about this unless the player's life can be bumped from 100 life to 120 life. The reason why 120 life is critical is because it allows the player to survive a phantasmal bolt, which is always the first attack the Moon Lord does that can actually reach the player through the blocks. The bolt can be exploited to knock the player into a teleporter, the same way every other boss knocks the player into a teleporter linked to a damage prevention machine.

Alas, since I wanted to do a run with minimal gear, I kept the life to 100 and thus took a (minimal) risk at the Moon Lord arena. That arena took a long while to build, since none of the existing arenas were good enough. It takes about 30 minutes for spear traps to kill the Moon Lord, and thus the arena has to be specially engineered so that the player never takes any damage. I succeeded - see the schematic below, but it took a while.

One final note: it was with some stroke of luck to discover that a meteor landing on and destroying a Demon Altar will trigger the generation of hardmode ores and enable the spawning of mech bosses! For some reason this doesn't work on Crimson Hearts, so the world must have corruption, not crimson. You can incidentally force the meteor to spawn where the altars are by placing treasure chests everywhere else - meteors do not strike within 25 tiles of any chest or NPC! To spawn the meteor, I blow up every shadow orb with explosives, which are wired to the teleporters connecting the WoF arena and the mech boss arena.



Schematics:


Skeletron + Lunatic Cultist Arena:


Mi8MbV2.png


23UTgIY.png

Wall of Flesh Arena:


QH1Ii5F.png


WtwZjPT.png

Mechanical Boss Arena:

qF2XFGo.png


kBImgKx.png

Plantera Arena:


imsbaXa.jpg


DXRXtF3.jpg

Golem Arena:

AjccPiq.png


lfcncTx.png

Lunar Event Pillar Arenas:

h569juN.png


fOhR9ZV.png

Moon Lord Arena:

h3CnOxn.png


FsMjxaw.png


World Download:

https://drive.google.com/file/d/0B4b_4cIU1vVBRkNfczAtdHdEOWM/view?usp=sharing

To do an automated run, follow these instructions:

1) Create a new character and load the world Omega_Prime
2) Open chest and equip the Platinum Armor set and Obsidian Skull
3) Use the teleporter to teleport to the dungeon entrance
4) Click the Old Man, and enable the curse

At this point the game will be fully automated. You will however have to left click on the Lihzahrd Altar to summon the golem once you reach the Temple (you'll have to wait for a Power Cell to drop first). Note that it might take a long while to get past the mechanical bosses (somewhere around 4-6 hours usually).

Also: there is a very tiny chance that the Moon Lord will clip the player when it first spawns in, ending the run, and nothing can be done about this. If the player can survive the Moon Lord's entry, the Moon Lord will not be able to hit the player from that point onwards.


Acknowledgements:

@stefnotch, @five--three, and @FSG Gaming for their work on Mechmod - the T-MEC community mod:
http://forums.terraria.org/index.php?threads/mechmod-a-t-mec-community-mod.38088/page-2#post-848106

@Thiner for proposing the fall-damage invulnerability machine, and for @stefnotch, @ZeroGravitas, @z26, and @Bahamut2001 for working out most of the details:
http://forums.terraria.org/index.php?threads/a-new-type-of-invulnerability-machine.27586/

To everyone for posting positive comments and feedback!
 
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DicemanX

Brain of Cthulhu
This is awesome. How long did it take you to make this?

Construction only took a couple of days total, but the testing took about a week. I ran portions of the map overnight each night I could, and a few runs were killed by some random oversights during building. The longest bit of construction was the Moon Lord arena - I knew intuitively that I could make one so that the player evades all damage, but it took a while to figure out the proper dimensions and timing. The previously showcased arenas (Blackshadowwind's, Bahamut2001's, and my own) work fine when fighting the Moon Lord with 500 life and a massive Stardust Dragon, but a 30 minute fight with a 100 HP character is a different story :).

Pretty fun constructional exercise!
 

DicemanX

Brain of Cthulhu
The EoW is not optional, because you need to kill it for voodoo demons to spawn(Or BoC)

I just noticed that the wiki mentions this, but I can confirm the wiki is incorrect, at least as far as update 1.3.0.8 goes. The voodoo demons currently spawn without beating the EoW or BoC, since I've been getting them to spawn the moment I would go down to the underworld on any freshly-made world (I even tried again 5 minutes ago by creating a new world and using RoD to go straight to the underworld). The playthrough demonstrated this as well - the world I used has no bosses killed on it, as can be confirmed by TEdit.

This is the most insane thing in all of terraria, although I know you'll probably surprise us all and do something even more crazy.

I'm a bit surprised myself that I can somehow keep topping some of my previous efforts, but I suppose it comes from learning from past builds and learning what can be achieved in this game. In fact, what inspired me to do the automated playthrough was a little bit of lo-tech I discovered when building the WoF recursive autofarm a couple of weeks ago: using the Hungry to knock the player into a teleporter as a way of detecting when the WoF spawns. This was the all-important key to automation of the game :).
 

Dragonfthirteen

Terrarian
LOL, got a Godly cascade when farming voodoo demons.
EDIT THE WIKI
[DOUBLEPOST=1451404846,1451404435][/DOUBLEPOST]
the Moon Lord can kill the player when it spawns in if the player gets a very unfavorable spawn. The Moon Lord can release an eye so that it positions itself over a player teleporter, and it will kill the player (200+ damage) when the player eventually uses that teleporter. The chances of this happening are fortunately very small. Nothing can be done about this unless the player's life can be bumped from 100 life to 120 life. The reason why 120 life is critical is because it allows the player to survive a phantasmal bolt, which is always the first attack the Moon Lord does that can actually reach the player through the blocks. The bolt can be exploited to knock the player into a teleporter, the same way every other boss knocks the player into a teleporter linked to a damage prevention machine.
I've had that happen on your farm
 

DicemanX

Brain of Cthulhu
LOL, got a Godly cascade when farming voodoo demons.
EDIT THE WIKI
[DOUBLEPOST=1451404846,1451404435][/DOUBLEPOST]
I've had that happen on your farm

With 500 life and high life regen you can survive 3 hits, which is the most the ML will do if you get an unfavorable spawn at the beginning - if you still end up dying then something went really wrong. It's also possible to get randomly hit by the true eyes later in the fight, but a strong enough Stardust Dragon kills the ML so quickly that the eyes cannot pull off enough consecutive damage to kill the player. Still, I could now swap arenas with the one from this playthrough, or better yet I could do a slight redesign and eat the first hit on purpose in a specially designed waiting chamber to knock me into a teleporter and not take any further hits.
 

Porky Minch

Terrarian
This has given me the idea of taking whatever loot the moonlord drops and starting a fresh playthrough with just that weapon. I'd have to leave Terraria running overnight, but it would be cool nonetheless.
 

five--three

Skeletron
*bursts into applause*
This is seriously awesome work. I'm completely dumbfounded ... great job!

I'm curious about a few things. I understand the mechanic behind the invulnerability machines, but how do you recognize that a boss has been killed? This can be overcome for most of the fights by simply waiting, but the Mechanical bossess in particular intrigue me. Since there's so much chance involved between the meteor landing and the the bosses themselves spawning, does it ever fail? Is there a way to determine if a Plantera's Bulb has spawned?
 

DicemanX

Brain of Cthulhu
*bursts into applause*
This is seriously awesome work. I'm completely dumbfounded ... great job!

Thanks, I appreciate it!

I'm curious about a few things. I understand the mechanic behind the invulnerability machines, but how do you recognize that a boss has been killed? This can be overcome for most of the fights by simply waiting, but the Mechanical bossess in particular intrigue me. Since there's so much chance involved between the meteor landing and the the bosses themselves spawning, does it ever fail? Is there a way to determine if a Plantera's Bulb has spawned?

The mech arena has a cascade timer that determines the length of the battle (there's actually a timer at every boss arena, but the pillars use a refreshing timer mechanism). Since the spear traps beat bosses in a fairly predictable amount of time, I took the longest amount of time needed (skeletron prime) and added an extra 30 seconds as buffer, and made the cascade timer equal to that amount of time. At the end of the cascade, I get returned to the waiting chamber or I get sent to the plantera arena if it was the 3rd mech - there's a counter mechanism upon exiting that keeps track how many times the player entered the arena. Also, the player only triggers the timer cascade if a boss knocks the player into the teleporter to initiate the battle.

Regarding the plantera bulb, there is a system in place that "checks" every minute whether a bulb has spawned. When the timer cascade reaches the end, the player is teleported out, stops the timer cascade, and then gets teleported to a chain of bulb farms, rapidly actuating then deactuating the jungle grass blocks along the way. If no bulb breaks, the player is returned to the waiting chamber and restarts the timer cascade, and the process repeats. If a bulb does break, the player still returns to the waiting chamber but then is subsequently knocked by plantera into the teleporter leading to the damage prevention machine. The timer is thus allowed to continue past the 1 minute mark while the spear traps kill plantera, and when the timer cascade reaches the end the player gets teleported to the golem arena.

From testing I believe the entire system is foolproof except at two points:

1) An unfavorable Moon Lord spawn can kill the player if the Moon Lord launches an eye at the start to one of the teleporter positions
2) A solar eclipse that starts at the 4th pillar will hold the player there instead of allowing the player to teleport out, and the moon lord will show up to kill the player

Nothing can be done about these two points, but fortunately both are pretty rare, especially #2 (which has around a 1% chance of happening)
 

PapaBear

Empress of Light
Wow! Impressive build!

I tried running @DicemanX's world and had a bit of bad luck. It took 14 hours (35 nights) to fight all 3 of the mechanical bosses. (It could have been worse... crunching the numbers, there is about a 31% chance that it might take *longer* than 35 nights... for the really unlucky, there is a 2.5% chance that you might have fought none of the bosses after 35 nights.) Everything went somewhat smoothly after that (23 minutes for Plantera, 8 for Golem, 5 for the Cultist and about 4 minutes for each of the pillars) until reaching the Moon Lord and (ouch!) then died about 2 or 3 minutes into the fight.

My own tweak, of having the player wear a gold watch, might have subtlely changed the timing of the teleporters and caused my demise or this might be the issue that @DicemanX mentioned earlier (although I would have expected that to happen immediately, not minutes into the fight).

As a suggestion, if the player dies, would it be possible to restart at the cultist fight? Right now, the player can be teleported back to the dungeon but the spiky balls aren't released to kill the cultists.

Thanks for an entertaining build!
 

DicemanX

Brain of Cthulhu
Wow! Impressive build!

I tried running @DicemanX's world and had a bit of bad luck. It took 14 hours (35 nights) to fight all 3 of the mechanical bosses. (It could have been worse... crunching the numbers, there is about a 31% chance that it might take *longer* than 35 nights... for the really unlucky, there is a 2.5% chance that you might have fought none of the bosses after 35 nights.) Everything went somewhat smoothly after that (23 minutes for Plantera, 8 for Golem, 5 for the Cultist and about 4 minutes for each of the pillars) until reaching the Moon Lord and (ouch!) then died about 2 or 3 minutes into the fight.

Thanks for trying the run yourself! That was indeed some bad luck waiting on the mech bosses, although the expected waiting time is 12 hours (10% chance per night, so the expectation is to fight a mech boss every 240 minutes or 4 hours). The plantera time was solid at 23 miutes - when I began construction I was worried that it would take forever for a bulb to spawn, especially since much of the natural jungle is intact, but the bulb spawn times have been quite short.

I'm quite curious what happened at the Moon lord fight though. The Moon Lord has three attacks to be concerned about - the first is planting a Sphere right at one of the teleporters when he spawns in, and the second and third are the Spheres and Bolts he fires at the player once centered in the arena. The teleporters are spaced and timed in such a way as to always be too fast for the Bolts, and too slow for the Spheres - as the video shows and as testing has shown the player is supposed to be untouchable, but apparently I missed something! In your fight, can you check whether it was a bolt or sphere that killed you? The gravestone should tell you. Also, in which of the teleporters was the gravestone? Finally, were you watching the fight, and if so, was the Moon Lord centered in the arena when you died?



As a suggestion, if the player dies, would it be possible to restart at the cultist fight? Right now, the player can be teleported back to the dungeon but the spiky balls aren't released to kill the cultists.

Yes, you can restart the fight. The only thing that doesn't get reset is the dummy hoik track that's part of the timer in the moon lord arena. The track is used to keep track of 5 minute increments by actuating a hoik tooth every 5 minutes. The entire timer mechanism is set for 40 minutes, but its only purpose is to automatically send you to the victory room, so it can be safely disabled if you're OK ending the fight in the ML arena.

To restart the fight, you can teleport to the dungeon entrance just like you did at the start, but you'll have to connect the left teleporter where you stand to the leftmost teleporter in the track below (where you teleport to from the golem arena) and use a switch to jump into that bottom track. You'll have to walk into the pressure plate leading to the arena for the lunatic cultist once all the regular cultists are dead.

I'm planning to update this map, and one of the things I'll be adding is a reset to the timer mechanism in the Moon lord arena. I will also be adding the aforementioned switch to the dungeon entrance to start the lunar event again.


Thanks for an entertaining build!

Glad you liked it! I certainly had a blast putting it together!
[DOUBLEPOST=1451749286,1451748579][/DOUBLEPOST]Incidentally, there might be a way of detecting the Moon Lord spawn by using what is essentially a NOT gate. The NOT gate would start off by releasing a bird from a bird statue into a 1x2 area with two pressure plates that the bird would continuously activate. Activating a pressure plate either keeps refreshing a 1-second timer or keeps a dummy ghost from reaching the end of a track. This serves to prevent a signal from being sent from the timer or from the end of the track so long as the bird is alive.

When the Moon Lord spawns in, he immediately fires off several shots that don't pierce through tiles but they do splash damage when they hit. If those shots can kill the bird, it would thus send a pulse a moment later to teleport the player from the waiting chamber into the chain of teleporters around the arena. This way, the Moon Lord spawn position can be controlled and prevent an early death that would otherwise happen from an unfavorable spawn.
 
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PapaBear

Empress of Light
Thanks for trying the run yourself! That was indeed some bad luck waiting on the mech bosses, although the expected waiting time is 12 hours (10% chance per night, so the expectation is to fight a mech boss every 240 minutes or 4 hours).

The way I figure the probability of something happening in some number of trials is to use the binomial probability formula. For normal Terraria chances, such as a 2% chance to drop something, the formula to see if it *won't* happen in N tries is to use this formula: (1 - p)^N. For example, to see what chance you have of not getting the drop after 50 kills would be (1 - 0.02)^50 or 0.364 or 36.4% and a 63.6% chance of getting the drop in 50 kills or less. Similarly for a 10% per night after 10 nights (240 minutes), that would be (1 - 0.1)^10 or 0.349, meaning that 34.9% of the time, a run would not produce one of those 10% events in 10 nights. It is a bit more complicated to figure out what is the chance of not getting 3 events in 30 nights where the calculation becomes one of adding together the probabilities of getting only 0, 1 or 2 successes in 30 trials. This is

probability of 0 bosses fought after 30 nights: (1 - 0.1) ^ 30 +
probability of exactly 1 boss fought after 30 nights: 30 * (1 - 0.1) ^ 29 * 0.1 +
probability of exactly 2 bosses fought after 30 nights: (30 * 29)/2 * (1 - 0.1) ^ 28 * 0.1 ^ 2

Adding those 3 terms together works out to be about a 41.1% chance of a run taking more than 30 nights to fight all 3 bosses or, conversely, a 58.9% chance of fighting all 3 in 30 nights or less. Crunching more numbers, the point where you have about a 50/50 chance (actually 49%) of finishing all all 3 boss fights is around the 26th night (10 hours 24 minutes).

I'm quite curious what happened at the Moon lord fight though. The Moon Lord has three attacks to be concerned about - the first is planting a Sphere right at one of the teleporters when he spawns in, and the second and third are the Spheres and Bolts he fires at the player once centered in the arena. The teleporters are spaced and timed in such a way as to always be too fast for the Bolts, and too slow for the Spheres - as the video shows and as testing has shown the player is supposed to be untouchable, but apparently I missed something! In your fight, can you check whether it was a bolt or sphere that killed you? The gravestone should tell you. Also, in which of the teleporters was the gravestone? Finally, were you watching the fight, and if so, was the Moon Lord centered in the arena when you died?

I know that the player was killed by a sphere but the world has been wiped out so I can't tell you which teleporter. I did watch the battle with the Moon Lord but it was pretty confusing, bouncing all over the place so I am not sure how centered he (or it?) was. I have resisted using the new mechmod but really should to stop that infernal bouncing and save my eyes. :merchantconfused:

Thanks for the other advice. I'll try it again when the new world comes out.
 

DicemanX

Brain of Cthulhu
The way I figure the probability of something happening in some number of trials is to use the binomial probability formula. For normal Terraria chances, such as a 2% chance to drop something, the formula to see if it *won't* happen in N tries is to use this formula: (1 - p)^N. For example, to see what chance you have of not getting the drop after 50 kills would be (1 - 0.02)^50 or 0.364 or 36.4% and a 63.6% chance of getting the drop in 50 kills or less. Similarly for a 10% per night after 10 nights (240 minutes), that would be (1 - 0.1)^10 or 0.349, meaning that 34.9% of the time, a run would not produce one of those 10% events in 10 nights. It is a bit more complicated to figure out what is the chance of not getting 3 events in 30 nights where the calculation becomes one of adding together the probabilities of getting only 0, 1 or 2 successes in 30 trials. This is

probability of 0 bosses fought after 30 nights: (1 - 0.1) ^ 30 +
probability of exactly 1 boss fought after 30 nights: 30 * (1 - 0.1) ^ 29 * 0.1 +
probability of exactly 2 bosses fought after 30 nights: (30 * 29)/2 * (1 - 0.1) ^ 28 * 0.1 ^ 2

Adding those 3 terms together works out to be about a 41.1% chance of a run taking more than 30 nights to fight all 3 bosses or, conversely, a 58.9% chance of fighting all 3 in 30 nights or less. Crunching more numbers, the point where you have about a 50/50 chance (actually 49%) of finishing all all 3 boss fights is around the 26th night (10 hours 24 minutes).

Yes, those calculations look good for determining probability of 3 bosses being fought within X day/night cycles. However, I was referring to the EV, which is more useful because it indicates how many cycles on average you'd be expected to wait before encountering all 3 bosses. Since the EV is the the probability-weighted average of all outcomes, I believe the calculation would go like this:

EV=3(1/10)^3 + 4(3C2)(1/10)^3(9/10) + 5(4C2)(1/10)^3(9/10)^2 + ... + n[(n-1)C2)(1/10)^3(9/10)^(n-3) where n is a very large number

The xCy function is the combination function. The 3, 4, 5 etc at the start of each term in the series refers to the number of day/night cycles and each of these numbers is multiplied by the probability of getting 3 mech bosses to spawn in exactly that many cycles. The probability of getting 3 boss fights in exactly n days is:

[(n-1)C2]*[(1/10)^3]*[(9/10)^(n-3)]

which simplifies to:

(1/2000)*(n-1)*(n-2)*(9/10)^(n-3)

The reason I'm using (n-1)C2 (and not nC3) for the number of arrangements of 3 nights with boss spawns and n-3 nights without boss spawns is because the 3rd boss spawn must always fall on the nth night.

So now we need to calculate this infinite sum:

EV=SUM(from n=3 to inf) n*(probability of 3 boss spawns in exactly n days)

EV=SUM(from n=3 to inf) n*(1/2000)*(n-1)*(n-2)*(9/10)^(n-3)

Let's bust out an online calculator:

http://www.wolframalpha.com/widget/...podid=Result&showAssumptions=1&showWarnings=1

The sum is 30, which makes sense since there is a 1/10 chance each day of getting a boss summon. In other words, the player will wait on average for 30 day/night cycles (or 12 hours) for all 3 mech bosses to spawn, assuming the calculations are correct.


I know that the player was killed by a sphere but the world has been wiped out so I can't tell you which teleporter. I did watch the battle with the Moon Lord but it was pretty confusing, bouncing all over the place so I am not sure how centered he (or it?) was. I have resisted using the new mechmod but really should to stop that infernal bouncing and save my eyes. :merchantconfused:

Thanks for the other advice. I'll try it again when the new world comes out.

Fingers crossed that you'll live the next time :).
 
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