Aliens, infinite score is possible.

General discussion on MAME, MARP, or whatever else that doesn't belong in any of the other forums

Moderators: mahlemiut, seymour, QRS

Post Reply
User avatar
RAX
MARP Knight
MARP Knight
Posts: 389
Joined: Fri Aug 19, 2005 5:45 am
Location: Bologna, Italy

Aliens, infinite score is possible.

Post by RAX » Thu Aug 25, 2005 5:28 am

I have discovered a technique to score infinite points in Aliens.
This technique avoid time-bomb from the ceeling by re-setting the invisible count-down timer, and is possible due to a programming bug. The invisible timer normally re-sets at the end of any sub-level, when CPU takes control of the character to move him to next sub-level, or to a monster, or so on. Sometimes the character falls, some other times he walks, many times the character takes a stair. In all these cases the programmers put a timer re-set, because the next sub-level or monster is a new timer session.
The bug is this: *even* the five in-level stairs use the same program routine, so climbing those stairs you get a new re-set of the timer.
Since two of those five stairs (the first and the third one) have one or two zombi nearby, it is possible (and also quite easy) to leech some points at a zombi, climb the stair (to avoid Hurry-enemies), and get down to score other points at the zombi. The timer re-sets to 4 minuts ad 15 seconds every time you get up or down the stair.
It is a very slow score increasing, but it appears to be infinite. You can use flamethrower (very easy), or three-way shot: this is a bit more dangerous, but if you get the right time you can kill some chestbursters while still jumping down the zombi. The definitive easiest way is at the third stair, killing the upper zombi and leeching with flamethrower to the lower zombi (two chestbursters killed out of three everytime).
Second and fourth stairs have no zombis nearby, but using them you get timer re-set.
Fifth stair (in the sewers) doesn't allow leeching, but you could anyway get an undeserved 10-15 seconds bonus by taking it (it's the time passed from the start of the sub-level).

This timer re-set sure happens in aliens, aliens2, aliensj and aliensu romsets. I couldn't test it on aliens3 or aliensj2 romsets, but I think it happens there too.


I am interested in scoring a record in this game, so I ask you to say what should be done to make scores be accepted by M.A.R.P.
I can propose two different ways to write a special-rule for the game:

1) "No stairs. Never.". This is very restrictive, since it makes impossible to reach even 4 energy bonus (2 every loop) and it forces to avoid up-level zombi's machine-gun's bullets.
But it is *sure* a complete solution to the "problem".

2) "Never leech at a zombi after having used any stair nearby". This is more balanced. Everyone in the planet, who played Aliens, climbed those stairs, unconscious of the timer re-set. I think the special rule should at least avoid abuse of the timer re-set.
But someone could say you get an undeserved advantage by resetting the timer: you could leech at the first zombi, at the second two zombis, and even at the barrels at the end of the sub-level.

I have submitted a little inp, about 40 minuts, to show an easy way to get infinite-playing. It's only to show it, I'm not interested in infinite leeching score. I am interested in a good special-rule.

Comments?

User avatar
mahlemiut
Editor
Posts: 4144
Joined: Mon Feb 04, 2002 10:05 pm
Location: New Zealand
Contact:

Post by mahlemiut » Thu Aug 25, 2005 6:37 am

You watched Gemant's inp first, right?

The timer resets whenever the screen scrolls, regardless of direction. When the "Hurry" signal appears, just make the screen scroll back and forward as little as possible. It'll disappear for a while.

But yes, it is rather boring (read "coma-inducing") to watch.
- Barry Rodewald
MARP Assistant Web Maintainer
Image

User avatar
RAX
MARP Knight
MARP Knight
Posts: 389
Joined: Fri Aug 19, 2005 5:45 am
Location: Bologna, Italy

Post by RAX » Thu Aug 25, 2005 7:02 am

mahlemiut wrote:The timer resets whenever the screen scrolls, regardless of direction.
I am not talking about that timer (that is 18 seconds), i am talking of the bomb timer, that has different value in any sub-level, and in that particular level is 4 minuts and 15 seconds.
Hurry appears after 18 seconds, and monsters appear after 12 seconds of hurry. If you scroll the screen even of one pixel hurry message disappear.
If you continue avoiding hurry-monsters (by scrolling screen) after 4 minuts and 15 seconds a bomb drops from che ceeling and kills you. Immediatly, no chance.
With my technique you have still to avoid hurry-monsters (that is what Gemant does), but you can continue indefinitely (that is what Gemant doesn'n, even if he takes unconscious advantage from timer re-set, just like every other player)
In my example inp (204100pts aliensj romset) i should die after 4 minuts and 15 seconds, but i continue leeching for 40 minuts, and die only for an error.
I've said "take stair to avoid hurry-monster" because you have to take the stair (before 4' 15") _and_ to avoid hurry-monster (before 30" (18"+12")): it's easier doing both actions together. If you go to the stair you scroll the screen of some pixel, then you could come back without taking the stair, but you must climb the stair at least one time every 4' 15". If not you die.

User avatar
mahlemiut
Editor
Posts: 4144
Joined: Mon Feb 04, 2002 10:05 pm
Location: New Zealand
Contact:

Post by mahlemiut » Thu Aug 25, 2005 7:37 am

Eh, maybe it's just me nodding off half the time, but it certainly seems like Gemant spends more than 4 minutes in some spots... (not counting against bosses, no hurry warning there)
- Barry Rodewald
MARP Assistant Web Maintainer
Image

User avatar
RAX
MARP Knight
MARP Knight
Posts: 389
Joined: Fri Aug 19, 2005 5:45 am
Location: Bologna, Italy

Post by RAX » Thu Aug 25, 2005 8:06 am

The timer starting value is different in any sub-level. In the first level it's 2' 10".
In the fourth level (queen alien's den) it's 8' 30".
At monsters you have no hurry message, but the timer is present, and if it goes zero the same bomb drops on your head.

The game would be (honestly) well-programmed. Limited time everywere, limited lives. You can leech for some time in every sub-level or monster, but if you don't proceed you dye. You can find the best place to spend all your lives leeching and dying, but if you don't proceed with the last life it's game over.
Gemant does this. He leeches in almost the game, he collects lives, and he uses them in fourth monster's room, then he finishes the game.

The point is that the bomb-timer limitation doesn't apply in the sublevel i described, because climbing the stair you get the timer re-set, and if you continue getting the stair you continue re-setting the timer.
It can be easily proven (if my inp is not enough). You can go to the second level and wait 4' 15" (obviously avoiding monsters and stairs). You will be killed by the bomb. If you use savestates you can save at 4'00" and wait. After 15" will drop the bomb. You load the savestate again and climb the stair. The bomb will drop 4' 15" after climbing the stair. In my inp i remain in the same position climbing&leeching for 40 minutes, and when i dye it's only for an enemy hit.

User avatar
destructor
MARPaholic
MARPaholic
Posts: 1969
Joined: Fri Sep 20, 2002 9:38 am
Location: Poland

Post by destructor » Thu Aug 25, 2005 10:59 am

RAX is right. Ghemant after 4 minutes go away because he run from bomb-timer. RAX talk that he don't run from bomb-timer, he hide on stairs. I must check it.

EDIT
I watched RAX inp. And yes, here must be rule against reset timer by use stairs.

User avatar
The TJT
MARPaholic
MARPaholic
Posts: 2473
Joined: Wed Mar 06, 2002 10:56 am
Location: 20 Grand Palace

Post by The TJT » Thu Aug 25, 2005 3:28 pm

Do you guys have a simple solution to become new special rules?
Ghemant?

User avatar
destructor
MARPaholic
MARPaholic
Posts: 1969
Joined: Fri Sep 20, 2002 9:38 am
Location: Poland

Post by destructor » Fri Aug 26, 2005 10:37 am

The TJT wrote:Do you guys have a simple solution to become new special rules?
Don't use stairs for purposeful bomb-timer reset. :roll:

User avatar
GHEMANT
MARP Seer
MARP Seer
Posts: 622
Joined: Sun Jul 28, 2002 7:11 am
Location: Italy

Post by GHEMANT » Fri Aug 26, 2005 11:49 am

the most functional solution is that to go up the ladder only once, kill the zombies, then recover the energies and going down the ladder and do not return on it anymore. In my recording i climb up once and then i climb down, so i die because of the time up and i return on the ladder to pick up the energy. The fact to climb up the ladder doesn't penalize me because i'd just lost a life and from that moment the time started from zero.

User avatar
The TJT
MARPaholic
MARPaholic
Posts: 2473
Joined: Wed Mar 06, 2002 10:56 am
Location: 20 Grand Palace

Post by The TJT » Sun Aug 28, 2005 10:05 am

Ok, special rules for Aliens +clones edited.

Obviously you cannot now climb same stairs up more than once, since that would be leeching.

User avatar
RAX
MARP Knight
MARP Knight
Posts: 389
Joined: Fri Aug 19, 2005 5:45 am
Location: Bologna, Italy

Post by RAX » Tue Aug 30, 2005 6:50 am

The TJT wrote:Ok, special rules for Aliens +clones edited.

Obviously you cannot now climb same stairs up more than once, since that would be leeching.
"Do not use the stairs on timer leeching purposes"
Sorry, but isn't it a bit vague?
I mean, even leeching at the first zombi, climbing, leeching at second two zombis, climbing, and leeching at the ending barrels is a timer leeching purpose IMHO. The sub-level is going to last more than 10 minutes in this case, when it was originally set to last 4' 15".
Is this way-of-play allowed by this rule?
Is allowed to leech in front of a zombi, climb the stair, and get down to leech in the back of the same zombi after resetting the timer?
Is it allowed to leech at a zombi for 4' 14", climb the stair one time only, and get down to leech again in front of the zombi until dying? It could be a 8'29" leech for any life.
I would say these and any other possible strange use of the stairs would be allowed if I die before 4' 15" or I reach the end of sub-level before 4' 15".

I completely agree with "I die, then I immediatly climb the stair to get energy: I get no real advantage."

User avatar
destructor
MARPaholic
MARPaholic
Posts: 1969
Joined: Fri Sep 20, 2002 9:38 am
Location: Poland

Post by destructor » Tue Aug 30, 2005 7:19 am

RAX wrote:I completely agree with "I die, then I immediatly climb the stair to get energy: I get no real advantage."
What knows 'immediatly'? 1 second, 2 ...? It's not clear. I think currently rule isn't the best but is good.

User avatar
RAX
MARP Knight
MARP Knight
Posts: 389
Joined: Fri Aug 19, 2005 5:45 am
Location: Bologna, Italy

Post by RAX » Tue Aug 30, 2005 9:07 am

destructor wrote:What knows 'immediatly'? 1 second, 2 ...? It's not clear. I think currently rule isn't the best but is good.
My last row was not a rule-proposal, but only a comment. Gemant told there is no advantage in taking a stair just after being dead, and I was of the same idea. Please forget my last row, because it wasn't the point.
The point is: when I abuse of the timer reset? In my opinion there are too many cases (and I have listed three different, but sure there are others) so that the rule cannot say which is allowed and which is not.
I suppose it's difficult to introduce a time rule like "Finish or die before 4'15" "
As I wrote in my first post, "Never leech at a zombi after having used any stair nearby" is for me the best balanced rule I can propose. Timer reset is useless if you can't leech points.
With my rule the maximum use possible would be leeching at every zombi for maximum 4' 15", with the side effect of 10+ minutes to get to the end of sub-level. But you couldn't climb one time to leech 4'15" more with the same life. With actual rule You can. IMO

User avatar
The TJT
MARPaholic
MARPaholic
Posts: 2473
Joined: Wed Mar 06, 2002 10:56 am
Location: 20 Grand Palace

Post by The TJT » Tue Aug 30, 2005 10:57 am

It's a bit hard to make strict rule and still keep all the old scores.
This rule allows you to leech as long as your toughest score competitor(marp 1st) It's a bit of honour thing, don't leech longer than your competitor has done. You should be able to know yourself when you are abusing timer-trick and when not. With this rule you can not leech infinite anyways.

For this kind of game, finishin-time(frames) based score would be best. But it would be unfair for old submissions to effect that kind of rule now.

----------------------------
If you simply cannot live with these rules, feel free to suggest a better rule using " "'s to make it 100% clear what your sugestion is.
But new rule cannot disqualify any previous (good) scores.
(It would be unfair, because players might have been "leeching" unknowingly. Plus disqualifying old recordings would allow for someone to ask new rules just because they cannot get first place, hehehe}

Post Reply