Re: Observations about the Ghost AI

PAC-MAN Championship Edition™

Observations about the Ghost AI

island mario 01-14-2008, 6:13 PM
Anyone else want to add their comments about the AI in Pac-Man CE?

Here are mine:

Blinky - I think he is the "smartest" of the ghosts generally, but there could be an argument that Pinky is smarter. An example of where Blinky is the hardest ghost, would be in a situation where you eat him, and he respawns while you are near their "home". You know that Blinky is coming straight after you. A weakness I have noted with blinky, is that he sometimes seems less likely to turn off a horizontal path (compared to Pinky) to get you. What I mean is imagine Blinky is going along a stright path towards the warp on the side of the board. If you are on a path where Blinky would have to come up or down to eat you, sometimes he will just keep going straight, whereas it seems Pinky would come get you more like 90% of the time.

Another example where Blinky doesnt seem 100% with it, is in Championship mode. Assuming youre familiar with opening patterns, when you eat the left dot, then right dot, then head back for the right dot at the bottom right, Inky will always come right towards you to meet you at the pellet. But if you had a slightly off pattern, where Blinky leaves the home before Inky, then Blinky doesnt come right at you, and seems to wander off. Maybe just an anomoly.

Pinky - arguiably smarter thank Blinky, you always have to watch out for Pinky. When I am playing, I tend to keep my eye on where Blinky and Pinky are at all times, as they are much more dangerous. Ive noticed that if Pinky can turn a corner to eat you, he most likely will. I never count on Pinky to 'give me a break'.

Inky - Smarter that Clyde, but not by much. There are lots of times where Inky could turn a corner to eat you, but he wont. Generally I dont worry about Inky too much.

Clyde - is pretty much random it seems. For this reason I think a lot of people hate him, because he will seemingly come out of nowhere and spoil an otherwise brilliant round. But for this same reason, I use his randomness to my advantage. Even if Clyde is coming right at you, there is a good chance he wil turn before he eats you if he has a chance. So if I am in a situation where Clyde and another ghost are coming to trap me, I *always* opt to head for Clyde, because there is a good chance he will randomly move out of my way, whereas if Pinky is coming at me, I know he will get me. For this reason Clyde has given me a multitude of saves, where it looks like I will die... I just hope for the best and a lot of the time Clyde pays off.

Ive tried to observe to see if there are more tangible ways they move. Im sure youve all noticed the phenomenon where when the ghosts are chasing you, and youre near a horizontal warp, sometimes they will go through and just leave you there with no ghosts left.

So what hav eyou guys observed?

Re: Observations about the Ghost AI

island mario 01-14-2008, 7:31 PM
I wanted to add another point I forgot. I do think the AI is ultimately predictable (i.e. it is based on logic) and not random at all.

as has been noted by others, I can start the game with the exact same moves hapening for some time, where there is clearly no random element. Ultimately, the patterns do not hold for more than a few boards, but I chalk this up to the minute differences in play that accumulate (i.e. turning a split second later etc).

my sense is that there is probably a logic to it. For example, Pink's logic might be "if pac man is lower on the board, turn down at the first corner" or things like that. Obviously it would be more complex than that, but I do sense some logic.

or perhaps there is a certain random element built in. Take my pink example above.... the logic might say "if pac man is lower on the board, turn down at next chance, except, randomly 10% of the time do not turn down.

anyways, just a thought.

Re: Observations about the Ghost AI

island mario 01-16-2008, 4:48 PM
lots of views but no replies... no one else has any observations?

maybe I am overthinking things :D

ive been playing championship mode for 3 weeks now (after giving challenge mode 1 a rest)... got up to 428K last night with 2 deaths... so Im hoping to climb to the top 20, or 10 if I can...

Re: Observations about the Ghost AI

island mario 01-25-2008, 9:23 PM
i realize i am basically talking to myself now, since no one else cares to contribute, but I think I am wrong in stating red is the smartest. there are defintely times when he impresses me more than pinky, but overall, red can still give some good breaks, where pinky is just scary

i really want to figure these ghosts out, as I am sure there is logic behind them. I am starting to wonder if the dumber ghosts like orange have simple lines in their programming like "if you can go up to eat pacman, go up, but if pac man is down, ignore him", or maybe things like "after 3 turns of pursuing pac man, go back to random pattern"

come on, some of you other top scorers must have something to add...

Re: Observations about the Ghost AI

Stephen El 01-26-2008, 11:43 PM
I think we're all busy playing!

My observation is that the orange is the "secret weapon" of the four. I can deal with the red and pink. Red is more predictably aggressive and follows you whenever you get near it... that's easy to deal with. Pink sometimes passed you by, especially if you are going from the bottom of a level to the top. I use that to my advantage in the beginning sometimes.

Orange, though, always seems to cross the board at the most inopportune moments; if you get anywhere near a warp and the orange one is on the other side, you can bet it'll enter the warp to get you from the other side as you cross.

Re: Observations about the Ghost AI

Vyriden 02-07-2008, 11:48 PM

Actually for me, Inky (blue) seems to always show up and ruin things for me at the worst moments. Blinky and Pinky are aggressive but they are fairly easy to predict. Clyde is pretty much totally random and is 'predictable' in that aspect (sort of like how Island Mario said). Inky however seems to be the least predictable of the four and in some ways that can make him quite dangerous in certain situations. He does seem to have a chase ability in his AI somewhere.

Inky's AI has always been somewhat of a mystery in all the Pacmans. Many have suggested different theories such as him randomly switching between the other ghosts behaviors. Another one is he uses Blinky's position and Pacman's position in an algorithim to decide where he goes. And another is that he never attacks head on and will vear off if you head towads him head-on (I'll have to test that one the next time I play) and only chases when he's near you. It's also been said he only chases when there are other ghosts around (I'm not sure about this one - he chased me before when it was just me and him).

Re: Observations about the Ghost AI

pacmantab 02-08-2008, 7:55 PM
Actually, if one were so inclined, you could develop a pattern that safely gets you through the game. Of course, it gets very difficult to hold a pattern past the key stage due to the increased speed.

Re: Observations about the Ghost AI

dynamatrix 03-04-2008, 1:22 AM

Hey Stephen I just want to say that I absolutely positively hate Clyde!! Hate him with a passion! Don't get me wrong you can definitely take advantage of his "stupidity" but more times than not the guy just ends up in the wrong place at the wrong time where I'm like, " Where the F*** did you come from?" No joke I think I've died at the hands of Clyde more than any other ghost.

Island Mario I agree with everything you said but believe it or not there are some occassions that Pinky will give you a break. IMO however I still think that Pinky is just dangerous. As you already pointed out you can take advantage of Blinky's aggressiveness. To sum it up the ghosts that I hate the most is Pinky and Clyde. I hate Clyde more though.

By the way I don't know how you guys consistently score in the 400k range. I can't even crack 400k yet. All I'm gonna say is that sometimes I think that my analog stick is possessed and has a mind of its own. There have been many times when I wanted to destroy my controller and yes even my HD set Surprise [:O]

Re: Observations about the Ghost AI

Stephen El 03-04-2008, 4:19 AM
Believe me, I was right there with you on the controller destroying, dynamatrix. I've destroyed three so far (two by throwing them against the wall, and the other wore out so much I got angry and tore it apart in my hands). I came close again tonight. I played two hours and could barely get past the first two minutes.

I was so angry and frustrated that I was playing so badly after such a long streak of good play that I had to step away and collect myself. I am so close to breaking my record again and getting to the next plateau of 470K+ that I played through it. Then, my last game, I got another 460K. I'm like seven days in a row without a score lower than 450K, which was almost impossible to even conceive of even a month ago.

My suggestion to you is to keep at it. Watch all of the YouTube videos you can and learn some patterns.

Re: the patterns. I don't doubt someone could play the same pattern the whole way through every time, but I'm just not that good. I messaged AlexTron69 a few times and he claimed to have a pattern he follows every time, but in my experience, I just can't play without having to constantly adjust my patterns on the fly. There are so many trouble spots in the game that I think I could hold a four week lecture series and still not cover them all.

I've played the first minute of Championship mode probably 1000 times at least, and there are portions of my pattern where, if I don't time my movement exactly right, it triggers the ghosts to go into another position. Some positions are favorable and others completely ruin the game.

There's a part of my pattern where I pause right before eating the fourth energizer to wait for Inky to go into a certain position because it triggers a favorable arrangement of ghosts for maximum points. If I move when he's off by even by few pixels, it triggers entirely different patterns depending on my timing. If I hit too early, I mess up the positioning and have to restart. If I hit a little early, I'm in good shape. If I hit in the middle, I'm in good shape. If I hit a hair late, I'm in great shape and can pull of an extra 3200 points. If I hit too late, I'm screwed and have to try to salvage it by pausing again at the end of the bottom, or I'll just start over.

If I weren't so lazy, I'd film myself doing this so you can see the vast differences one tiny move can make. Now imagine that carried throughout the entire game. There are situations like that throughout the entire game where one tiny fraction of a second can trigger the ghosts to move in different ways and mess you up!

Re: Observations about the Ghost AI

VaporPressure 03-10-2009, 9:42 PM
I too have thought about this. I'd say 95% of the time I get caught by Blinky or Pinky. Blinky is always the first guy out of the box, so he always has to be accounted for. I eat Blinky at every opportunity because of his tenacity. The only way Inky gets me is if I run into him. Clyde's unpredictability gets me once in awhile, but very rarely. Each one is definitely 'programmed' differently, and that's a great part of the game.

Re: Observations about the Ghost AI

TIGGER GB 03-15-2009, 10:54 PM
THE GHOST AI IN PAC MAN CE DEFINETELY DOES FOLLOW PATTERNS.I AM BASING THIS ON
ABOUT 3000 GAMES.THE KEY TO MANIPULATING THESE PATTERNS IS TO STICK TO ONE
PARTICULAR MAZE AND LEARN THE PATTERNS.SOMETIMES FRIENDS WATCH ME PLAY AND
ARE AMAZED AT THE NUMBER OF TIMES I 'GET AWAY WITH IT' WITHOUT BEING KILLED.

THAT IS BECAUSE I HAVE LEARNED TO ADAPT TO THE PATTERNS FOR MY BENIFIT.THIS OFTEN MEANS MOVING AROUND THE MAZE IN WAYS THAT ARE,ON FIRST GLANCE,ILLOGICAL.

WHEN PAC MAN FIRST CAME TO THE ARCADES I REMEMBER A FRIEND SHOWING ME A MAP
OF THE MAZE WITH DIRECTIONAL ARROWS THAT HE USED TO FOLLOW TO THE LETTER.HE GOT GREAT SCORES.IN THEORY,THE SAME PRINCIPLE COULD BE USED ON PAC MAN CE,BUT,THE SPEED OF THE GAME MAKES THIS UNWORKABLE.THE THING TO REMEMBER IS TO STICK TO ONE MAP,AND REMEMBER THE PATTERNS OF GHOST MOVEMENTS.I FOUND
MYSELF DOING THIS SUB CONCIOUSLY AND IT DEFINETELY DOES HELP.

A MUCH BETTER CONTROLLER WOULD ALSO HELP A LOT.HAS ANYONE WORKED OUT A WAY TO USE A ' PC ' STYLE JOYSTICK ON THE 360 ? IF SO I WOULD LIKE ONE.

IF YOU ARE A PAC MAN CE NUT LIKE ME,FEEL FREE TO ADD MY GAMERTAG TO YOUR FRIENDS LIST

TIGGER GB

Re: Observations about the Ghost AI

OzPatriot 10-05-2009, 3:28 PM
This thread is an excellent read and having played ALOT of this game now, alot of the observations made here are spot on.

Definitely true what you said Island Mario about always heading for Clyde in a tight situation because "most" of the time he will cut you a break. The ghosts ALWAYS give you an out at some point, its just a matter if your quick enough to take it and all that comes with experience.

I generally follow a set pattern and have a couple of alternates to always fall back on. I know there is a few stages where I will come through a port and pretty much know what ghosts should be where and I can then decide which energizer to go for first.

Sometimes I think the ghosts patterns are very dependent on where you are in relation to them and what pattern (board) you are on. You can also "manipulate" ghost patterns in a way especially Blinky and Pinky. On some stages to rule out them cutting off a path I may be heading I will get close to them then immediately change direction so then they follow me, essentially keeping them out of danger. Like others have said though, there is definitely a method to how each ghost works and I am doing my best to work it out somewhat, but I think it will always be a mystery as to exactly how they work.

To me though, the ghost that cause the most grief is Clyde. While his unpredictability can be used for advantage at times, other times not knowing causes that slight hesitation, which can cost you straight away or later in the game by putting everything that little bit out of sync.

"You have the Platinum medal...You know, it just might be an actual crime to ride that well"-Trials HD