Aztec monks with 1/55 HP no longer die when picking up or dropping a relic

https://www.reddit.com/r/Games/comments/12jbb9d/age_of_empires_ii_de_major_update_81058/jfy2mqq/

by danso • 3 years ago

525 208 3 years ago

mcraiha• 3 years ago

From the comments:

"This was caused by a floating point rounding error. A unit switching jobs internally becomes a different unit (i.e. a monk with a relic becomes a monk without a relic), and when doing that, HP is scaled proportionally based on the old and new max HP using 32-bit floating point maths."

And there are YouTube videos about this https://www.youtube.com/watch?v=MytWNbpnAVY

ReactiveJelly• 3 years ago

The formula was probably `return new_maxhp * (old_hp / old_maxhp);` ...
Due to floating point rounding errors, convert_hp(1, 55, 55) equals 0.999999940395355224609375, which is less than 1, which means the unit dies.

Ahh. The old "Multiplying and dividing is associative... for the set of reals, not for the subset that you can actually afford to compute with." So it should have been `(new_maxhp * old_hp) / old_maxhp`. ffmpeg has a whole AVRational class for the same type of problem when converting timestamps accurately between 2 timebases.

Reminds me of the TF2 ammo boxes that give 40 metal on Linux and 41 on Windows https://www.youtube.com/watch?v=QzZoo1yAQag&pp=ygUfdGYyIGhlY...

Apparently the compiler used on Linux chose a less-accurate multiply instruction for 0.2 * 200.

Two wrongs make a right - After being less accurate but rounding up where you don't need to, the Linux binary correctly arrives at 40, and the Windows binary arrives at 41.

For percents (and dollars) I always do everything in cents and divide by 100 at the very end. "20 * 200 / 100" can be done with pure ints, and f32 can represent i16 exactly.

zelphirkalt6• 3 years ago

Seems all that could have been avoided by using rationals in general and the condition for living being >0 instead of dying <1. Not sure in what case it makes sense to have dying at smaller than 1. To the user all the numbers are integers, so why not use rationals instead of floats?

The more I write code, the more I notice how rarely one truly should want floats in most kinds of programs and how they almost always carry a whole bag of problems with them.

thrdbndndn2• 3 years ago

Could you explain to a noob why does this happen, exactly?

Is it because 55/55 != 1, or 1*1 != 1?

I understand float can't store certain integer/finite decimal precisely, but why would a/a not be 1 if both numerator and denominator are the same (imprecise) number?

layer8• 3 years ago

So it should have been `(new_maxhp * old_hp) / old_maxhp`.

I don't see how that couldn't run into similar problems. I would use `clamp(old_hp * (new_maxhp / old_maxhp), 1, new_maxhp)` (assuming that old_hp >= 1).

pclmulqdq2• 3 years ago

If you have integers that are stored in floating point types and don't need more than [mantissa] bits of precision, you can operate on them like ints and always* get the right result. Nobody would expect that the formula `return new_maxhp * (old_hp / old_maxhp);` would work with ints, but they see floats as magic that allow them to drop their guard about precision and rounding of operations. Unfortunately not.

Rationals have a big problem where under multiplication and division they need to be re-normalized periodically, and that re-normalization is slow (running gcd). Under addition and subtraction, rationals are great.

*the one big difference is that division rounding is different

BeetleB2• 3 years ago

The old "Multiplying and dividing is associative... for the set of reals

Psstt... Dividing is not associative for the reals.

filmor• 3 years ago

None of these would be a problem if people would round instead of truncate by default.

m4632• 3 years ago

I wonder if the fix would be vulnerable to "nudging" hit points up by picking up and dropping a relic? :)

intrasight• 3 years ago

I woke up in the middle of the night and of course opened up HN. This was near the top and was an interesting read.

I told my GF that last night I had insomnia and found myself researching why Aztec monks die when picking up a relic, and that doing so resulted in plumbing the depths of an important computer science topic.

She said "Sounds like you were reading Hacker News". She knows me so well now :)

riffraff2• 3 years ago

This is a fantastic out of context change log.

For even more abstract ones I cannot recommend enough the Dwarf Fortress Bugs Twitter account[0]

The last of which is

Flying creatures keep exploding into pieces and dying: Are they crashing into trees?

[0]sadly no Mastodon, https://twitter.com/DwarfFortBugs

a_e_k• 3 years ago

Paradox Interactive games, especially the Crusader Kings series also have some pretty entertaining change logs. E.g., from Crusader Kings II, Patch 2.4 [0]:

- Handsome and lustful men now also populate the cabins in the wild for the pleasures of people who find them attractive.

- Characters who love their spouses very much are now less likely to join holy orders.

- Paranoid parents should no longer worry about potential plots against dead children.

- Fixed that bedtime stories can no longer be told to dead children

- You no longer punish yourself when a prisoner tries to flee from your prison by charming the guard.

- The Orthodox Patriarch is now concerned if Orthodox rulers have heathens in their court.

- Discovering two vassals of the same sex engaging in carnal activities during pagan feasts no longer let's the liege join in on the fun.

- Ambitious claimant adventurers now move out of the realm if they are targetting their liege

- No longer possible to banish your spouse or concubine

- Decreased monthly decadence gain.

[0] https://forum.paradoxplaza.com/forum/threads/patch-2-4-chang...

m4632• 3 years ago

Wow, the logic to model these kinds of social structures makes my head hurt. But you would have to do it.

And I wonder about dead children. I remember one game where there could be no dead children.

riffraff2• 3 years ago

These are great, they make me want to play the game!

Although I'm not sure why a threesome during a pagan festival has become illegal, I'd have considered that a feature, not a bug.

acheron• 3 years ago

There was a bug fix in Nethack a few years ago to make eating parchment spellbooks break vegetarian conduct. Which at one level makes perfect sense: of course parchment is an animal product. But the fact that it comes from the intersection of several kind of weird systems in the game made it such a great Nethack bug. First, that the game tracks vegetarianism at all. Then, the randomized unidentified item descriptions that are mostly flavor text but occasionally have gameplay properties. And finally, why are you eating spellbooks in the first place?

schoen• 3 years ago

As opposed to eating rings, which can permanently give you the associated magical intrinsics (without having to wear the ring). This, in turn, means that which specific intrinsics you can get that way various from game to game (because you can temporarily polymorph into a metal-eating monster, but some rings are metal and others aren't).

https://nethackwiki.com/wiki/Eating_jewelry

system2• 3 years ago

I was stopping myself from buying Definitive Edition but I guess I am buying it today...

dragontamer7• 3 years ago

Note that the April 2023 patch is live, and perhaps one of the biggest changes to the meta ever. I don't think anyone really knows how the new meta will shake out.

Build orders will absolutely change this patch. Though I guess that only matters if you were hoping to get to a competitive level.

Definitive Edition does have a very good tutorial mode for people interested in online combat, and "Extreme" AI is 100% legitimate (AoE2 Extreme does NOT cheat, you're fighting it fair-and-square, but Extreme does a proper build order so it just "feels" quick if you haven't studied build orders yet)

fauxpause_3• 3 years ago

What’s new? Seems kind of crazy to introduce a meta changing past to an old game like this that has managed to stay popular.

vippy2• 3 years ago

What's up with all of these 18 feudal builds?? And to Hell with the Portuguese fast castle, organ gun OP on arena.

vippy2• 3 years ago

ok, but who but TheViper or DauT has this issue? ಠ_ಠ (As a Japanese main, nerf Aztecs.)

moneywoes• 3 years ago

Wow this comment had me reminiscing of watching AocZone tournaments replays of them in my youth

Sigh

spaceman_20202• 3 years ago

Always a little surreal to see the Viper still around. He used to be a legend in the forums 20 years back.

arendtio2• 3 years ago

The T-West video talks about a match between Mr. Yo and Valas ;-)

olalonde• 3 years ago

Fun fact: The competitive AoE2 scene remains very much alive and thriving. Several top players are able to make a living from it, thanks to streaming revenue and tournament prize money. There are even some streamers, such as T90 and MembTV, that have managed to create successful careers despite not being competitive players themselves.

dragontamer7• 3 years ago

Note that T90 is like 2300 Elo. Which isn't "top level pro", but I'm pretty sure he'd kick most of our asses.

T90 is probably the strongest dedicated commentator / announcer / caster in this community.

justrealist• 3 years ago

tbh I credit ZeroEmpires with keeping the community alive through the slower times though.

arendtio2• 3 years ago

And some players have come a long way. One of my highlights was, when DauT won the Red Bull Wololo 3 tournament as someone who is playing the game 20+ years. And some fans are doing great stuff too, like this video that was released shortly after (DauT is back):

https://www.youtube.com/watch?v=_u-SisO8ers

lippihom2• 3 years ago

I've never seen this video. Hilarious / awesome.

Sniffnoy• 3 years ago

Rather than linking to this Reddit thread, wouldn't it make more sense to either link to:

* The linked-to patch notes? https://www.ageofempires.com/news/age-of-empires-ii-definiti...

* The particular comment explaining this bug fix? https://old.reddit.com/r/Games/comments/12jbb9d/age_of_empir...

danso• 3 years ago

I tried to and thought I had linked to the comment. I did wonder if the link went only to the thread, but the Reddit mobile web interface is so broken that I couldn't tell where the link was going to, though I figured the Aztec monk bug would stay at the top either way so people would figure it out.

(the official patch notes don't explain the bug)

vishnugupta• 3 years ago

What’s the best way to play AoE on a MacBook? I can’t afford a dedicated game rig so any pointers would be of great help.

Sakos2• 3 years ago

This is what I found for the M1 https://old.reddit.com/r/macgaming/comments/ms8081/age_of_em...

Seems to work fine with Wine and Crossover.

steivan• 3 years ago

I use a small machine at Paperspace (P4000 with 100GB) and play it remotely with Parsec. The experience is very good and costs me about 10-15$ a month.

moffkalast• 3 years ago

How is it that a modern laptop manages to be worse at gaming than the average PC 20 years ago? Surely you one can at least run it in an emulator of some kind?

rwalle• 3 years ago

Probably not the answer you were expecting, but you may want to consider getting an Xbox Series S (that is often on sale at $250 or even $200), plugin your mouse and keyboard and you'll have a great experience. Yes that is a "dedicated game rig" but much more affordable than a usable gaming PC. Of course, only if you also play other games on that xbox and can live with no disc. This is what I would do in your situation.

Reason0773• 3 years ago

It’s great that Microsoft are still actively maintaining a ~24 year old game!

Blizzard ought to take note. A few years back they announced “Warcraft 3 reforged” with great fanfare: a remastered version of the classic Warcraft 3, updated for modern systems with improved graphics etc. It looked/sounded fantastic!

But despite it being a paid upgrade, what they released was a buggy mess that did little justice to the classic original. Then they immediately abandoned it and have released no updates or fixes since.

potemkinhr• 3 years ago

It's actually worse, they pulled the legacy version from the users and forced the (effectively) downgraded version to everyone. Even the owners of the legacy version were shafted as they forced a update which removed much of the functionality of the legacy version. To this date still the best version was the pre-patch one for everyone who has the original installers and the latest pre-upgrade patch

zelphirkalt6• 3 years ago

And the AoE2 DE has way higher system requirements while only looking marginally better in some aspects, but looks worse than 2 decades old 2d art in some other aspects. Just because it "has to be 3D" these days, while there is nothing truly requiring any 3D in the game.

This is subjective, but I liked some of the old unit designs more than the new ones. For example Teutonic Knights and Cataphracts looked better in my opinion. The Teutonic Knight looked leaner and taller, while it now looks a bit like a walking barrel. OK, somewhere they need to carry all that armor ... but still I liked the old ones better.

Also I would have been completely fine with units having only 8 or whatever directions in which they can look. I don't need 360° all-around rendering of units. It even substracts a little from AoE2's abstract character.

What I do like is, that they added more civs.

Laaas• 3 years ago

I'm surprised this isn't illegal.

Razengan• 3 years ago

This kind of crap is actually why I will not buy Diablo 4 (even though I kinda want to, to have a good hack'n'slash on my PS5) or put money into any Blizzard game anymore.

Reason0773• 3 years ago

Update: In fairness to Blizzard, I did just check this again and it seems like they have started maintaining Warcraft 3 Reforged again, releasing some small patches last year and a significant update in January 2023:

https://news.blizzard.com/en-gb/warcraft3/23896791/warcraft-...

I'll have to take another look now that this has been released.

But still, there was a 2 year stretch between 2020 and 2022 when the game was in a very crappy state and absolutely nothing was done to improve it or address the issues.

yen223• 3 years ago

It's not just maintenance, Microsoft has released several expansion packs to the original Age of Empires II, plus an Xbox port to boot.

tetha2• 3 years ago

Yeah it appears my Diablo 2 has been pulled from my Blizzard account when the D2 Remastered was launched, at least I can't find it anymore. And now I either have to dig up the CD and key and hope those still work or pay $60 or something to play D2. My desire isn't really that big.

alewi481• 3 years ago

I see this link on the Blizzard support site that provides downloads to classic D2 and LoD but I haven't tested them out to see if they ask for a CD key or not.

https://us.battle.net/support/en/article/13867

spaceman_20202• 3 years ago

The amazing thing is that this new version of AoE was a fan made upgrade, and they did such a good job that MS brought them in house.

The Forgotten Empires team is brilliant and I can't be more grateful to them for bringing back a childhood favorite.

lippihom2• 3 years ago

It's really been amazing. Also very cool how much the community has grown in the past few years. The subreddit is super active which adds to the fun.

roflyear• 3 years ago

Broodwar is still super popular and they don't do shit there either.

hannofcart• 3 years ago

Even more amazing still is that it still has a large active player base and YouTube streamers make money playing it and casting videos of their play through. I'm routinely shocked by how easily I can join online multiplayer matches.

For a 24 year old game!

A bunch of guys in my company play it. Most of them were 3 or 4 years when the game was released. A couple of them weren't even born.

Real kudos to the team maintaining it. They constantly listen to player feedback and keep updating the various unit stats and bonuses to keep the game balanced.

shilgapira2• 3 years ago

What a weird coincidence. I thought at first this would be about the Guild Wars game, but turns out they both have something to do with monks and 55:

https://wiki.guildwars.com/wiki/55_Monk

voz_• 3 years ago

Ahh nostalgia. I thought so too. This was such a fun build. I miss GW1 a lot, GW2 missed the mark, and is no true successor.

Sakos2• 3 years ago

Man, I miss GW1. That skill/class system was amazing and still goes unmatched in its flexibility and depth today.

zeeZ• 3 years ago

Depends on what you're after. In terms of mechanics it's a completely different game, but lore wise a phenomenal amount is tied in to GW1. It's almost fan service: the game.

hobofan• 3 years ago

Yeah, really the only word out of place in the headline was "Aztec". All the rest could have applied to GW.

Fun fact: In the early days (I think the first 6 months or so) of GW there were some item attribute modifiers that I think allowed for going as low as 5 hp, making the character basically invincible, as all damage was rounded down.

dvngnt_• 3 years ago

farming ectoplasm lfg

dimgl2• 3 years ago

Wow, another 55 monk enjoyer. I used to farm hydras outside of the Crystal Desert with this.

shilgapira2• 3 years ago

There were dozens of us, dozens!

winrid• 3 years ago

Immediately noticed how the font on the MS's site is very readable. "noto-sans", evidently

userbinator• 3 years ago

My metrication extension turned the title into "Aztec monks with 13.37 W no longer die when picking up or dropping a relic".

Taywee• 3 years ago

That's not a lot of power for a monk. What's the typical monk's TDP?

sprain• 3 years ago

Not knowing it was about a game, that was one of the strangest headlines ever to read on here.

0xpgm• 3 years ago

Likewise, I thought it was something to do with blood pressure :)

neom• 3 years ago

Conversely, I didn't even have to even click in to understand it hah. Been playing AoE for around 20 years.

alternatetwo2• 3 years ago

I was confused as well, because I just had chatted with someone about whether the aoe2 monk conversion ability on certain buildings was hardcoded or not (they can't convert i.e. Town Centers, Monasteries) ... turns out it at least used to be, no idea about now.

celeritascelery• 3 years ago

I don’t understand why they didn’t just use an integer. You can’t have half a HP in AoE and nothing has HP so high that it would overflow a 32 bit integer. Seems like it would avoid a lot of problems.

mqus• 3 years ago

Afaiu there are compounding factors like 1.5 here and 1.5 there should result in 2.25 and so on

adameasterling• 3 years ago

I had a really fascinating conversation with the lead architect at Frost Giant the other day. They're making the next StarCraft, basically.

They don't use floating points.

He didn't mention (IIRC) the possibility of rounding bugs; the reason he cited was something a bit more interesting: Floating points are not deterministic, which makes multiplayer challenging, as they simulate game state on each client's computers and only send commands across the wire.

One wonders if the "out of sync" errors that plagued Age of Empires in my youth were partially explained by FP determinism issues!

account424• 3 years ago

Floating point numbers are deterministic, they just depend on thread-global state which has different defaults on differen platforms and can be changed by third-party libraries (including injected ones) at any point.

qprofyeh• 3 years ago

Guess that’s what those Epsilon checks are for.

devjab• 3 years ago

The thing I like the most about this is how the game actually switches out a unit with a different unit depending on the task the unit needs to do. It's not exactly in the reddit post, but rather in the video https://www.youtube.com/watch?v=MytWNbpnAVY where the error is outlined. What a brilliant way to keep complexity down.

agumonkey• 3 years ago

When read with a history bias, that title makes for a long and deep source of confusion.

dragontamer7• 3 years ago

I mean, Age of Empires 2 is a very historical game. Everyone knows that the Halberdiers of the Inca are pretty good especially when paired up with Inca's famous archers: their Crossbows and Arbalesters. /s

These historical games have two ways of doing things. Staying historically correct (which is unbalanced... such as Hearts of Iron where Soviets + Germany will likely crush Poland in the first move every game), or you balance the game so that everyone has a fair chance like AoE2. But balancing the game naturally introduces significant ahistorical aspects.

--------

AOE2's historical campaigns are pretty good though, and somewhat representative of famous battles throughout history.

syspec• 3 years ago

This game is still amazing. I never played it as a kid, but bought the Definitive Edition last year on steam. Already have > 600 hours on it.

Beat RTS ever in my opinion.

Check out big tournament to get an idea of the current scene: https://youtu.be/6krbA4jTUqE

Also I didn't play multiplayer until last month, most of that 600 hours was spent in the many many excellent single player campaigns

raldi• 3 years ago

I would consider banning implicit casting of floats to ints from the codebase: Nobody would have intentionally truncated in this HP conversion; they would’ve rounded.

einpoklum• 3 years ago

It's an unfortunate consequence of compatibility with C.

I'm pretty sure you could get the compiler to warn you about this stuff though.

elnatro• 3 years ago

Is Age of Empires playable in MacOS? I’d like to remember my childhood years but going back to windows after 15 years of Ubuntu and MacOS gives me headaches.

alternatetwo2• 3 years ago

You're a decade too late, there was a ppc port for MacOS back then ...

ummonk• 3 years ago

Suppose someone with 1 hitpoint actually transformed into a unit with less hitpoints - should they then die? Seems to me the fix should be to represent hitpoints as integer values, and round up during conversion.

1024core• 3 years ago

I had no clue what the headline was all about. I imagined some Aztec monks with a 1/55 HP motor trying to do something and just dying for no reason.

boosteri• 3 years ago

Well, once it's out it's out. O can just imagine fixing this would break some clever mod/campaign featuring deadly relics that monks are forbidden to touch.

account424• 3 years ago

What kind of monster would write this as `new_maxhp * (old_hp / old_maxhp)` instead of `(old_hp / old_maxhp) * new_maxhp`.

Aztec monks with 1/55 HP no longer die when picking up or dropping a relic

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