PC A new type of invulnerability machine

[Thiner]

Theory:
As far as my exploration in the code of Terraria, the processes that affect invulnerability of the player can be ordered in the following order: (I only listed the terms that caught my interest, and if you want to know the invulnerability source that I omitted, tell me and I may refer to it in source code)
Falling Damage > Mount Damage and Dash damage (Although it is mobs that are attacked, it grants the player immunity) > melee damage > lava damage > smashing-a-pre-hardmode-demon-altar damage > projectile damage
Note:
1. If the hurting tiles haven't been deprived of general immunity, they should be after melee damage.
2. melee damage and projectile damage are calculated in the order of index. An NPC with a smaller index has higher priority. That's why normal invulnerability machine requires you to avoid friendly NPC death and eliminate natural spawn before spawning the critical slime.

About the Falling damage, I didn't try it, but it might work if you repeatedly teleport yourself to a higher place and hoik you downwards so that you take a 1 fall damage consistently with a interval of no more than 20 frames without a Cross Necklace, and 40 if you have. The falling damage override all the immunity, and actually, it just ignores the immunity and set it to false before you take fall damage. So you have flexible intervals between each 'fall'. I didn't try it, anyway, so give me example!

Actually what interested me is the second term. I just say it explicitly: If I dash through a line of Target Dummies riding a Unicorn, I will have a line of invulnerability. I think it is very easy for the devs to fix it, though. (Am I too naughty?)
But things get interesting once it starts. Even if Dummies can not grant immunity any more, well, there should be something that have ability to grant immunity, unless the devs remove the immunity line completely in all the section of codes.

So invulnerability machine is not just a honey-soaked slime statue with precise control of mobs in the world, or a blanket of spikes to walk upon. You can think of more types of invulnerability machine to make yourself immortal before the devs manage to ban it!

 

[ZeroGravitas]

but it might work if you repeatedly teleport yourself to a higher place and hoik you downwards so that you take a 1 fall damage consistently

Beautiful, that's just what I was thinking of after your first paragraph, there. In fact, you don't need a teleporter, a simple hoik loop of just the right height/dimensions will repeatedly bash the life out of you like a demonic washing machine (from past experience). Be fun to tweak this to just the right damage level, add in a heart statue and jobs done. The same hoik loop could trigger traps, etc.

I'm thinking a 2 teleporter (only) drop, activated by player hitting a plate at the bottom, would be prettier, but might not be possible, since it would TP you away before you could actually hit the ground (probably).

I wonder if fall damage is most likely to stay usable, since you never want to be able to block death by falling... Although, sure they could just re-write it as a parallel damage source, if this method got too popular. (I see you've already conversed with @HotPocketRemix about Moon Lord damage patches in the 1.3 changes thread.)

If I dash through a line of Target Dummies riding a Unicorn

Lol, surreal! And totally beyond my experience. Hope there's still some craziness left by the time I get there.

Might be pretty cool to maintain a small index of these methods (e.g. here, in first post, or a new thread), with a small picture of each method, links to an example and a status note (about if/when it was patched).

 

[z26]

"I'm thinking a 2 teleporter (only) drop, activated by player hitting a plate at the bottom, would be prettier, but might not be possible, since it would TP you away before you could actually hit the ground (probably)."

Might be possible to add a 1 frame delay mechanism for that. teleporting + hoiking a npc in a small loop?

 

[ZeroGravitas]

it would TP you away before you could actually hit the ground

Indeed it does. So have the first plate hoik you a step to the side, activating the teleporter from a second plate a tick (or more) later. Use the horizontal hoik length to fine tune the damage timing (if it's not too far out) plus pick up hearts.

 

[z26]

basically a simpler, more elegant version of what I was proposing =)

The only thing i'm worried about is whenever repeating fall damage fast enough to be immune 100% of the time is possible.

 

[Thiner]

basically a simpler, more elegant version of what I was proposing =)

The only thing i'm worried about is whenever repeating fall damage fast enough to be immune 100% of the time is possible.

You should try it out yourself, although as far as I see in the code, fall damage can override all the damage types including previous fall damage (it unconditionally disable general immunity and reset it), and will always grant general immunity(in contrast with the hurting-tiles immunity and the moon-lord immunity) for a normal time(20/40/40/80 ticks under different conditions) after the damage is taken.
I think the unicorn invulnerability machine is easier to build and use, though... Well, although it seems to be closer to a bug, before the target dummies are fixed...

Well, about testing I usually use Chest Statues to summon deadly mimics when I test my invulnerability machine... Although when it fails I am likely to die in the machine...

 

[z26]

I've given this a quick try and found out that (at least when using zero's proposed method) there's a delay of a few frames between activating a hoik button on the gound and suffering the fall damage of said ground, meaning that if you only hoik left\right during one frame, then teleport, you still don't get any fall damage.

With that said, not saying this technique doesn't work, just saying it will need a better implementation than mine and\or more delay.


EDIT: I implemented something that causes fall damage repeatably. However, the blinking times out between each cycle. If there is any way to lenghten the immunity time it might work. currently the (unoptimized) mechanism hurts you a bit more often than one time\second

Another edit: Did it with a cross necklace and it works! the mimic can't hurt me.
(with that said I still haven't got around to the healing part, but with 16 defense you only are hurt for 2 damage each fall.)

Yet another edit: I've now added a 1-sec timer activated heart statue. Also put a cross necklace in a chest. Therefore, the contraption while ugly, is fully fonctional. Here is the very messy world I've made this in if anyone want to try out the machine for whatever reason https://www.dropbox.com/s/5lehlo1wqh6zdrd/fall damage.wld?dl=0

 

[ZeroGravitas]

and it works!

Nice. Indeed it does! Z26's fall damage invincibility setup (left):

I tidied and simplified your wiring (right). And when finely tuned for 2 damage, you should only need one heart statue, I think. A single hoik step to the right was not sufficient to activate fall damage (as you say), but 2 was. Tested verses lava too, but someone should give it a go with Moon Lord, see if it is the ultimate cheese machine.

Notes:

• You have to take more than 1 damage otherwise invulnerability time is cut in half, which is too short for the fall duration, even with the cross necklace.
• Minimum fall damage at 0 defence seems to be 10 (via this method), so ~16 defence is the first sweet spot for minimising this to easily managable levels.
  
• Knock-back blocking item (e.g. cobalt shield) should not need to be equipped (come to think of it), provided immunity stays perfect.
• You don't need to have the top teleporter pad floating (and actuated) if you just raise the lower pad up a couple of blocks (and hammer it to use as the hoik).
  
• Minecarts could have been used in place of hoiks, except you need to hit blocks first to take any fall damage. You'd need a little delay mechanism to actuate those blocks... Or... Fall onto a teleporter pad directly with the pressure plate activating the pad via a short delay, e.g. statue mob relay. In fact, that would obviously work without the minecart too, negating the need for hoiks either!
  
• Alternatively, I'm pretty certain this could be made with just a hoik loop, making it pre-hard-mode, pre skeleton even, if you are able to set up on some trap of (e.g. dungeon) lighting wire (for the heart statue).
• Camp-fire, heart lantern and pots might be enough sustain without any wiring (hoik loop).

 

[z26]

Thanks for tidying this up for me!

cobalt shields are indeed not needed, derp XD

credits for Thinner for coming up with the idea and you with the implementation, I only followed your directions =)

the two statues were because i like the redundant redundancy.

I can't test this with the moon lord sadly, I'm not that far in terraria 1.3. But if I get to him someday ill try this out.

 

[Thiner]

Thanks for tidying this up for me!

cobalt shields are indeed not needed, derp XD

credits for Thinner for coming up with the idea and you with the implementation, I only followed your directions =)

I can't test this with the moon lord sadly, I'm not that far in terraria 1.3. But if I get to him someday ill try this out.
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No way. As far as I see, the devs think that we are naughty, so they just use a parallel immune timer for the Moon Lord. But for all the other bosses, it is useful and, if able to implement early, really helps in most cases (if uses pure hoiks, ever since the EoC) and helps a lot to progress faster than expected ...

By the way I saw some strange things. How can a statue be put on a sloped tile? I mean the heart statue on 2 hoik blocks.

 

[ZeroGravitas]

credits for Thinner for coming up with the idea and you with the implementation

Ideas are cheap and so is my rambling, it takes someone to actually make the effort to get these things rolling. Good job.

How can a statue be put on a sloped tile? I mean the heart statue on 2 hoik blocks.

I know, right? Didn't used to work, does now in 1.3! If you shape the block first, then place it down. Pretty cool. Can also place furniture onto platforms that form part of stairs when they have an adjacent platform (so it looks like they should be able to support something)! Except I just had trouble with a glass grandfather clock, kept popping back off a glass platform stair for no particular reason.

they just use a parallel immune timer for the Moon Lord

So you sound pretty adamant that will include fall damage too, fair enough, good to have diversity in fight requirements.

The problem with using this kind of immunity mechanism is being able to do enough damage to finish them off in time. If you can't get a line of sight, or the screens moving too much. The pre-wire bosses, you have no traps to use (and no minions per-say), and the late game bosses take too little damage from traps (although, perhaps summoner class comes into it's own more by then, nowadays).

 

[Gandalf K]

 

[Thiner]

Maybe the reason why I failed is that I only used 1 dummy. 2 dummies might be what it needed to work successfully...

 

[ZeroGravitas]

Nice demonstration video @Gandalf K

2 dummies might be what it needed to work successfully...

Just to be clear here, are dummies actually necessary for this exploit, or just a convenience? (Could a good, stable source of mobs be used (almost) as sucessfully? I mean, the DG dodging immunity is granted by the mount's player invulnerability trigger, right?

Mount Damage and Dash damage (Although it is mobs that are attacked, it grants the player immunity)

I presume they added this invulnerability as a work-around so player would not also take damage when a mount bops a baddie on the head? (Because the 'mount' is actually just a visual part of a modified player sprite & hit box, yes?). So how long is this cool-down, exactly?

 

[Thiner]

Just to be clear here, are dummies actually necessary for this exploit, or just a convenience?

The latter. If you use slime statue along with ghost-dummy engine when equiping royal gel (or not), you will harvest the same thing theoretically.(Well in practice I didn't try that, haha)

So how long is this cool-down, exactly?

I think you meant invulnerability period. Actually both sides gained invulnerabilities
(ticks)
Slime: 6 for the player and 10 for the enemies.
Unicorn: 6 for the player and 30 for the enemies. (Unicorn dashing is 45 tiles per second, 3/4 tiles per tick.)
(All in codes)
Other dash attacks: (well.. I didn't look inside the code because I think it is impractical to harness. Tell me if you need it)

 

[ZeroGravitas]

(ticks)
Slime: 6 for the player and 10 for the enemies

Cool; well there you go then, you need to be hitting an 'enemy' 10 times per second (i.e. every 6 ticks) to maintain perfect invulnerability. So with only one mob (or dummy) there will be 4 ticks after your 6 ticks invulnerability ends during which you could take damage (including getting insta-jibbed by by DG). Of course that's assuming you are always overlapping a target, the physical dimensions of the setup used need to keep you in contact.

I thought I'd head they had fixed the direct DG slime mount exploit, as shown here:

...But did they just make it so that bosses don't trigger the 6 tick invulnerability? (Hence you need the foil mobs there continuously now?)

 

[Thiner]

But did they just make it so that bosses don't trigger the 6 tick invulnerability?

It seems like that even the Moon Lord can grant immunity for mounts. Well, I mean general immunity, so you can't immune his damage for 6 ticks after you have stamped on him using slime mount or dashed through him on a Unicorn..
It applies to other bosses, although the other bosses can be immunized by the 6 ticks' general immunity.

I think the way they fixed is just the 6-10 difference. The enemies can be invulnerable for more time so you will be hit once if you still collide with him on a mount.

(I am constantly rambling theories without much testing... You can make more test.)

 

[ZeroGravitas]

(I am constantly rambling theories without much testing... You can make more test.)

Mah, I'm just 'shooting the breeze' myself because I'm not in a cognitive state where I'm able to do anything more constructive. That's what you people are for!

I think the way they fixed is just the 6-10 difference.

Yes, you're quite right, that does make perfect sense: the mount's hit attack will be checked for (and hit) first, a higher priority than the mobs melee attacks on you. But they can get you the second time around whilst they are still invulnerable, since it won't proc the mount's on-hit invulnerability. Right. (And you think you ramble! Good to be clear on things though, it opens doors to further ideas.)

So, are mounts like swords, in that they are limited to the number of mobs they can hit (to e.g. one per tick)? [Seems so: pic] If so, that should mean that once you have 5 DGs on you (for example), their invulnerability start times will get staggered by at least 1 tick, bridging your window of vulnerability. So the dummies should only be needed to bootstrap, if you can get half a dozen enemies on you simultaneously...

It's a tricky exploit to fix entirely without being too heavy handed, I think. Mario style jump-on-their-heads mechanic is wonderful fun, would be a shame to loose it's pop.

 

[Thiner]

their invulnerability start times will get staggered by at least 1 tick

At least 1 tick. Also note that only when your velocity.Y is positive(you are falling) can you deal mount damage.
But I don't see other limit in this issue.
All the limits:
You are riding a mount, and the mount is slime mount, and you are not in water(well slime floats and fluctuate on water, so this effect should be negated), you are falling, and the game found an NPC that:
collides with you(well there are some strange details, if you see some strange occurrence, I may look through it carefully), not something that doesn't take damage(blazing weel in the dungeon) or in a state that doesn't take damage(BoC first form, maybe), not friendly(well, the dummies are not friendly, and note that slimes are not friendly in the game code when you have Royal Gel equipped), and not immune to the player.
The game will only let the slime mount bump on one NPC at a frame.

And you think you ramble! Good to be clear on things though, it opens doors to further ideas.

At this time I can't access the Terraria itself, so I just watch the code rambling some values that occur in the code... Well when it is the time that I have access, I will just play it.

 

[Brain Goo]

I've checked the machine on a pumpkin moon and unexpectedly reached reached a final wave on 9:7 PM and got 92k points + 45 plat in the end of the night.
I'm not wearing a dragon armor here and the accessories are not perfect, I think the result can be improved to about 8 PM!
The idea is that your dragon is damaging mooring wood on the spawn surface and you kill pumpkins with a solar eruption.
I'm also surprised that I didn't got much more money than DicemanX and his ultimate 1.2.4.1 farm, so I'll add some chests to quick stack items and I'll see if the problem is in the item limit.