00:00
[disk drives beeping]
00:02
[deep electronic music]
00:07
I developed a storyline for Shadow Man.
00:09
He comes back at predetermined moments through the game.
00:13
There's one point where he steals a potion.
00:15
Just as you're about to reach it,
00:17
Shadow Man comes running in,
00:18
drinks it and runs off.
00:20
There's another moment where you're about
00:22
to get through a gate,
00:23
Shadow Man walks up,
00:24
steps on the pressure plate,
00:25
and closes the gate.
00:27
At that point, you fall back down three levels,
00:29
and you're gonna have to work your way back up.
00:31
These encounters were scripted
00:33
to make you hate Shadow Man
00:35
and see him as your enemy,
00:36
so that by the time you face him with crossed swords
00:39
at the end of the game,
00:40
you really wanna get this guy
00:41
because he's set you back so many times.
00:43
It's a way to build an emotional relationship
00:45
between the player and an opponent
00:47
through the actual gameplay
00:48
rather than just telling it in a cinematic.
00:51
Hi, I am Jordan Mechner,
00:52
creator of Prince of Persia.
00:53
This is how I animated myself into a corner
00:56
and had to fight my way out.
01:02
So I was a kid in New York in the mid '70s.
01:07
I grew up on MAD Magazine,
01:08
and if computers hadn't come along when they did,
01:11
you know I might have ended up doing comics, animation,
01:14
but when the Apple II came in 1978,
01:16
I saw this as a machine that I could
01:18
first of all use to play games at home
01:20
which was never possible before.
01:21
Instead of taking rolls of quarters down to the local arcade
01:24
I could stay at home and play Space Invaders
01:26
on the Apple II as much as I wanted.
01:28
The computer was also a way that I could
01:31
and I became fascinated with that.
01:33
This is before the Internet,
01:34
so pretty much everybody was self taught.
01:37
I subscribed to Creative Computing magazine,
01:39
and then a little later Softalk magazine
01:41
which had articles about how to program,
01:43
and then I would trade tips
01:44
with my friends who were also into computers.
01:57
So my first games were copies of existing arcade games,
02:00
and you always had three lives,
02:01
and the goal was to get a high score,
02:03
but now I was a freshman in college,
02:04
and I wanted to do a game that would tell a story,
02:07
so that's when I started programming the game
02:09
that would become Karateka.
02:10
[bright synthesizer music]
02:14
It was a very simple story.
02:15
The princess has been kidnapped by the evil warlord
02:18
who has taken her to his castle,
02:19
and so as the hero you have to
02:21
fight a series of karate battles
02:23
with the warriors who are guarding the fortress.
02:26
So you're basically running from left to right,
02:28
you fight one warrior after another
02:29
until you reach the end,
02:30
and then you fight the big bad guy
02:33
and rescue the princess,
02:34
so the computer that I was working on was the Apple II,
02:37
and at that time the Apple was actually
02:39
the number one game platform,
02:40
but it had limitations.
02:41
The Apple II's music capabilities weren't that great,
02:43
it only had four colors,
02:45
the screen was 280×192 pixels,
02:47
and everything had to fit into 48K of memory.
02:50
That was pretty much a hard limit.
02:52
In those days this was before Photoshop,
02:53
this was before we had graphics and animation tools,
02:56
if you wanted to put a character up on the screen,
02:58
you pretty much had to do it pixel by pixel,
03:00
so when I tried to do the animation for the character,
03:03
I found out pretty quickly that it just looked stiff,
03:05
and it didn't just have the lifelike quality
03:08
that I was imagining in my head,
03:10
so I used a technique called rotoscoping
03:12
which actually has a long history.
03:13
It goes back to the early days of film animation.
03:15
Early Disney animators used film footage
03:18
as reference for the animation in the early films.
03:21
If you look at Snow White,
03:22
the human characters like Snow White and the Prince
03:24
were actually animated using rotoscoping,
03:26
which means that the Disney animators
03:28
filmed live actors doing the moves
03:30
that they needed to animate onscreen,
03:31
and then they would actually project these frames,
03:34
and copy or trace them frame-by-frame
03:37
to create the animation that we've seen.
03:39
So I did that for Karateka.
03:40
I used Super 8 film to film my karate teacher
03:43
doing the kicks and punches,
03:46
that I needed the character to do on screen,
03:47
and then I traced each Super 8 film frame
03:50
with tracing paper and pencil,
03:52
and then translated those into pixels
03:54
to get it up on the screen.
03:55
That was kind of the rotoscope 1.0.
03:57
[synthesized electronic music]
04:00
Karateka came out in 1984,
04:02
and it became a number one bestseller,
04:04
so this was really lucky for me
04:06
that it happened when it did,
04:07
because as I graduated from college
04:09
instead of going out and getting a job
04:11
I actually had the luxury of thinking,
04:12
What do I wanna do next?
04:14
And I had an idea to do another game.
04:16
One of the inspirations was the first 10 minutes
04:18
of the movie Raiders of the Lost Ark.
04:20
[suspenseful orchestra music]
04:23
If you remember Indiana Jones in the opening sequence
04:25
runs jumps over a pit almost misses,
04:29
spikes spring out of the wall,
04:30
there's a gate that's closing,
04:32
and to me, those actions kind of matched
04:34
what I was seeing in platform games,
04:36
like Lode Runner and The Castles of Doctor Creep
04:38
where you'd step on the pressure plate,
04:40
it would open a gate.
04:41
I thought what if we combined that gameplay
04:43
with a character who's so human feeling
04:45
that you feel like if you miss the jump
04:47
and you fall it's really gonna hurt.
04:48
Because in the early platform games
04:50
characters were kind of weightless.
04:51
You know you would jump, and you would make it or not,
04:53
but you would float down to the bottom
04:56
It didn't feel like you could really get hurt.
04:58
So my idea was to kind of combine
04:59
the basic platform puzzle type gameplay
05:02
in sort of a modular environment
05:03
with very smooth visceral running and jumping animation
05:07
that would capture the excitement
05:08
of the opening minutes of Raiders of the Lost Ark
05:10
[dramatic orchestral music] [man grunting]
05:17
The story of Prince of Persia was also simple.
05:20
Like Karateka, it involved rescuing a princess.
05:22
And it was really inspired by
05:25
the Thousand and One Nights
05:26
and by movies like the 1940 The Thief of Bagdad
05:29
in which an evil grand vizier has seized power
05:32
and imprisoned the princess.
05:34
For Prince of Persia I knew
05:35
I was gonna need so much more animation
05:37
Running, jumping, climbing, falling:
05:39
all the movements that the little character
05:41
would have to do on screen.
05:42
And by the the time I did the animation
05:43
for Prince of Persia in '85,
05:45
a new technology had come along, VHS.
05:47
So using one of the early VHS cameras,
05:50
I videotaped my brother running and jumping
05:52
and doing all those things in the parking lot
05:53
across the street from our high school
06:01
Get up get, up get up!
06:03
And then the problem was
06:04
how to get these videotaped frames into the computer.
06:06
After a bit of trial and error,
06:08
the technique that I finally settled on
06:09
for Prince of Persia
06:10
was a kind of analog-to-digital to analog-to-digital
06:13
and involved several steps.
06:15
I took the video tape of my brother
06:17
and put that on a TV screen in a darkened room
06:20
put a 35mm camera on a tripod
06:23
aimed it at the TV screen
06:24
and then took a picture,
06:26
did a frame advance on the VCR,
06:27
took another picture,
06:29
frame advance, frame advance, frame advance
06:31
then I took that roll of film containing about 35 frames
06:35
down to the local Fotomat, the one hour photo
06:37
had the film developed
06:38
and then got back a sheaf of snapshots
06:40
which I then Scotch taped together
06:42
and using a Sharpie and Wite-Out
06:45
highlighted the outlines of each character
06:47
then put that on a Xerox machine
06:49
and came out with one clean sheet of paper
06:51
with a series of frames of a clean white character
06:55
against a black background
06:56
so that contrast was sharp enough
06:58
that I could then put that piece of paper
06:59
on an animation stand,
07:01
pointed a video camera at it,
07:02
and ran that into the Apple II which had no video in.
07:05
This was a special digitizer card
07:06
that could get one clean still image.
07:09
It couldn't capture motion,
07:10
but once I had that sheet of nine or 12 individual frames
07:15
I could then go in pixel by pixel and cut them out
07:17
on screen using my animation tool
07:19
and then run those frame in sequence,
07:20
and so all of this took weeks of work
07:23
to get from that video tape run or jump
07:26
to the point where the game was actually playing back
07:28
those frames in sequence on screen.
07:34
When I first saw that character running
07:35
and jumping on the screen,
07:36
it had the rough illusion of life and of weight,
07:40
but these were the days of eight-bit graphics.
07:42
Each frame of animation in Prince of Persia
07:44
was a series of bytes that represented
07:47
a fixed image on the screen,
07:48
and then the next frame of animation
07:50
was another set of bytes,
07:52
so to do something like jump in place took 12 frames,
07:55
to do a running jump might take 15 frames,
07:58
and the number of frames made the animation smoother.
08:02
So once you add the jumping, the running, the turning,
08:05
the hanging, the swinging, all of these things,
08:08
each individual movement took memory.
08:10
This is where one difference between computers then
08:13
and now became very important
08:14
because the Apple II's memory was 48K.
08:18
That's less than a normal text email,
08:21
so that had to contain everything:
08:22
all of the images, all of the backgrounds,
08:24
all of the frames of animation,
08:26
all of the logic to make it work,
08:27
all of the sound effects, all of the music, everything.
08:30
So with all of the basic animations
08:32
that the character needed to navigate,
08:34
through the dungeons, that had filled up
08:35
all of the computer's available memory.
08:50
So it was June of 1988,
08:52
and I was two years into making Prince of Persia
08:54
and at this point I had done most of the heavy lifting
08:56
to get the game working.
08:57
I had a smoothly animated character
08:59
that was running through these dungeons
09:01
climbing and falling and stepping on pressure plates
09:04
to open gates and jumping over pits
09:06
almost falling on spikes.
09:07
Everybody who saw the game oohed and ahhed.
09:09
It was like a great proof of concept,
09:12
but it wasn't that much fun to play,
09:14
and I kind of had the sinking feeling as I realized
09:16
that I've done almost everything I meant to do,
09:19
but it just doesn't have that excitement
09:21
that I was hoping for.
09:22
Also there was a ticking clock
09:24
which is that the Apple II platform was dying.
09:26
When I started to make Price of Persia,
09:28
the Apple II was still the number one games platform.
09:30
By 1988, there were new machines that were coming out
09:33
that had more colors, higher resolution,
09:36
better sound capability,
09:37
and I was really at the tail end
09:39
of the Apple II's life cycle,
09:40
but I felt that switching to a different platform
09:43
would have been like starting over,
09:44
so the worry was that I could come out with a game
09:47
that was great, that was fun,
09:48
but nobody would ever play it.
09:51
Yeah so it was a problem when you reach a point
09:52
in development that makes you question your initial vision.
09:55
Sometimes the answer is to say,
09:57
you know just believe in the initial vision,
09:59
execute it, it's gonna be fine.
10:01
But sometimes you discover things along the way
10:04
that make you realize
10:05
that the initial vision is just a first draft.
10:07
From the beginning,
10:08
I had the idea that the main character would not fight
10:11
that this was a nonviolent character
10:13
just trying to survive in a dungeon in a violent world
10:16
that is there's spikes that spring out of the floor,
10:18
there's you know gates and falling blocks
10:20
that can crush you,
10:21
but this is not a violent character.
10:23
The point is just to get through these traps
10:25
and get to the end and rescue the princess,
10:27
and I had used all of the resources
10:30
that the Apple II offered to try to create this.
10:33
I didn't have room to put in another character,
10:37
so I was sharing an office with friends
10:39
who were also working on their own projects.
10:41
Robert Cook was working on a game
10:42
that became D/Generation.
10:43
Tomi Pierce was creating educational software,
10:46
and every time Tomi saw Prince of Persia on my screen
10:49
as she walked by my desk,
10:51
she would say, Combat, combat, combat.
10:54
or this game is not going to be fun.
10:55
and this frustrated me because I hadn't planned for combat.
10:58
Karateka was a fighting game.
11:02
you fight the guard,
11:03
and then on to the next battle,
11:05
and so I would explain to Tomi,
11:06
I can't do that because there's not enough memory
11:08
in the computer to also have a smoothly animated enemy
11:11
that does everything that I would need an enemy to do.
11:14
But when Tomi got an idea,
11:15
she wouldn't let it go,
11:17
and so I would add a new feature to the game,
11:19
I would say, Now there's torches on my wall.
11:21
Now I've got jaw traps that chomp and add suspense.
11:24
Isn't it better now?
11:25
Tomi would look at the new feature I added and say,
11:28
Combat, combat, combat.
11:31
And with frustration I realized that
11:33
there was something to what she was saying.
11:35
As much as I wish that it was almost done,
11:37
it just wasn't that much fun,
11:38
so this was the problem:
11:40
two years into development,
11:41
I'd used up all the memory to get as far as I'd gotten,
11:44
but the game was missing that suspense and excitement
11:46
and sense of conflict that had made Karateka
11:49
so simple and so much fun.
11:50
What was I gonna do?
12:04
So I can tell you exactly what happened.
12:06
On that day in June 1988,
12:08
because I wrote about it in my journal,
12:10
it was another day in which
12:12
Tomi had come and looked at my screen and said,
12:15
Combat, you need combat.
12:16
And again I'd rolled out my usual argument about how
12:19
first of all that's not the concept of the game
12:21
second of all there's no memory,
12:23
and she said, Well in 'Karateka,'
12:25
you used the same shapes for the hero and the enemy,
12:27
couldn't you do that?
12:29
I said, No, because the hero looks like a likable
12:32
enduring kind of character.
12:34
The enemy shouldn't look like that.
12:35
And she said, Well,
12:36
what if you made the enemies a different color?
12:38
And then the idea came to me,
12:40
what if I exclusive-or'd each byte with itself
12:43
shifted one bit over?
12:44
[keyboard clacking]
12:46
So the Apple II didn't have image processing
12:48
in any kind of sense that we understand it now
12:50
'cause the graphics were all bitmapped,
12:52
but one of the assembly language instructions
12:54
was called exclusive-or
12:55
which basically means if the the two bits are the same,
12:59
if the two bits are different,
13:01
so as I was telling Tomi for the 10th time
13:05
why I couldn't draw a character in a different color
13:07
than the one I originally created,
13:09
I realized that if I used the exclusive-or instruction
13:12
shifted one bit over,
13:13
this would create kind of a shimmery, ghostly outline
13:16
of the main character,
13:17
and as soon as I said those words,
13:19
the character's name popped into being: Shadow Man.
13:22
So with Tomi and Robert looking over my shoulder,
13:25
it actually look me all of five minutes
13:27
to write the code that would turn the main character
13:29
into a shimmery, ghostly version of itself,
13:33
and as soon as we saw Shadow Man running, jumping,
13:36
and climbing through the dungeon,
13:38
it became obvious that this was
13:39
this was the opponent that the game needed.
13:42
It was Robert who suggested
13:43
that Shadow Man could come into being
13:45
when you jump through a mirror,
13:47
your ghostly self jumps out the other direction
13:49
and then once it's loose in the dungeons,
13:51
it becomes your enemy,
13:53
closing gates that you wanted open,
13:55
and just kind of wreaking all kind of havoc,
13:57
so out of necessity was born this character
13:59
who ended up becoming one of the best features of the game.
14:02
It's a case of where constraints can sometimes push you
14:04
to more creative solutions
14:06
than you would have found in the beginning
14:07
if they had been available.
14:09
If memory had not been a constraint,
14:10
I probably would have created all kinds of monsters
14:13
and enemies in Prince of Persia to add a lot of variety,
14:15
but because there was no room for any of that,
14:17
I was forced to dig deeper and came up with Shadow Man
14:20
which ended up actually being kind of deeper
14:22
and more satisfying.
14:23
At the end of the game when you confront your shadow self,
14:26
and you fight him with swords,
14:27
every time you hit Shadow Man,
14:29
you lose a strength point,
14:31
and you realize that if you keep fighting,
14:32
you're eventually gonna kill yourself,
14:34
so the solution is not to win the sword fight,
14:36
but to put away your sword,
14:38
and when you put away the sword,
14:39
Shadow Man does the same,
14:40
and then facing each other,
14:41
you run towards Shadow Man,
14:43
he runs towards you,
14:44
and the two of you merge and are reunited,
14:46
and then you get back all the health points
14:48
that Shadow Man had stolen from you throughout the game,
14:50
and with this restored strength and wholeness,
14:52
you're then able to fight the grand vizier,
14:55
That's something that I wouldn't have come up with
14:57
if I didn't have to.
14:59
Once Shadow Man was in the game,
15:01
it was obvious that that was the right way to go,
15:03
and so I managed to squeeze out of the memory
15:06
enough frames to do sword fighting
15:08
so that you could fight the shadow version of yourself,
15:11
and that was so compelling that it's alright,
15:14
I've got to find a way to populate this dungeon with guards,
15:16
and at this late stage,
15:18
I've found a way to take 12K of memory that was hiding
15:21
in the auxiliary memory card of the Apple II
15:24
but this presented a new problem.
15:26
How do we create the animation for the enemies?
15:28
So the model for the animations in Prince of Persia
15:30
had been my younger brother who at this point
15:32
was 3,000 miles away,
15:34
and he wasn't any good at sword fighting anyway,
15:36
so my first attempt was to film myself
15:39
and my office mate Robert with a sword doing fencing.
15:43
Unfortunately, that didn't work.
15:45
Finally in desperation, I turned to one of my favorite films
15:48
the 1938 Robin Hood with Errol Flynn,
15:50
and it just happened that in this film,
15:51
in his climactic duel with Basil Rathbone,
15:54
there's a sequence of about six seconds
15:55
where the two characters are perfectly in profile,
15:57
fighting each other,
15:58
so with a VHS tape of the 1938 Robin Hood,
16:01
I took photographs of each frame of film,
16:03
and extracted the moves that the characters would need to do
16:07
in order to do sword fighting,
16:08
and once the guards were in there,
16:10
the game felt complete.
16:12
Now as you move through the dungeons,
16:13
you had that feeling of challenge,
16:15
of suspense, of fear
16:16
that had been such an important part
16:18
of what made Karateka successful.
16:29
The lesson, if there is one,
16:30
you know the best way that I've been able to formulate it
16:32
is that when you have these two voices,
16:34
you know two different approaches in your brain,
16:36
giving you two different solutions
16:38
that are diametrically opposed
16:39
to really try to tune into each voice
16:42
and think, Is this the voice you know of the big picture?
16:44
Because sometimes you can have great ideas
16:47
that are kind of taking you off the path
16:49
of what you originally set out to do,
16:50
but sometimes that voice is actually
16:52
putting you back on the path.
16:53
The reason that Shadow Man was the right thing to do
16:55
I think goes back to the original inspiration
16:57
of Prince of Persia.
16:58
It's basically the modern version of a swashbuckling movie,
17:01
and in those old swashbuckling movies
17:03
whether it was Errol Flynn or Douglass Fairbanks
17:05
or Indiana Jones, the hero did fight,
17:07
so it's completely in line with that spirit.
17:11
Prince of Persia released at the end of 1989
17:14
and as I'd feared, I'd lost the race against time.
17:17
By then, the Apple II was a dying platform,
17:19
and for about a year,
17:20
I had the agonizing experience
17:22
of feeling that this game that I'd work so hard on
17:24
which everybody who played was enjoying,
17:26
that this game was going to sink without a trace.
17:30
What saved it was the ports to other platforms,
17:33
to the PC, to the Mac,
17:35
and also to consoles
17:36
like Sega and Nintendo
17:37
that came out over the next couple of years,
17:40
and kind of rescued this game that had been a flop
17:42
and made it into a hit,
17:44
and that's what actually made it really clear to me
17:47
that adding Shadow Man and combat had been
17:49
the right thing to do
17:50
because on these other platforms,
17:52
the memory issues that had been so critical on the Apple II
17:57
Those swashbuckling cinematic roots turned out
18:00
to be a key part of you know what made Prince of Persia
18:05
Prince of Persia was successful enough on PC
18:07
that we did a sequel.
18:08
Prince of Persia 2: The Shadow and the Flame
18:10
and by the time this game came out in 1993,
18:13
we had a new generation of PCs that could do sound
18:16
and music and color graphics way beyond
18:19
what was possible in the late '80s,
18:22
and we took advantage of this,
18:23
adding more enemies, more characters,
18:25
and richer environments, sending the prince on a journey
18:28
across a world that got us of the dungeon and palace
18:32
of Prince of Persia 1.
18:33
But the basic gameplay,
18:34
the formula of traps,
18:36
fight and flight, puzzle solving,
18:37
and combat and exploration,
18:39
was still pretty close to what it had been
18:41
in Prince of Persia 1.
18:43
Since the original Prince of Persia,
18:44
the technology has advanced,
18:46
but the basic questions of game design
18:48
haven't really changed all that much.
18:49
When we did the remake in 2003,
18:51
Prince of Persia: The Sands of Time,
18:55
a much later generation of consoles.
18:56
The PlayStation 2 generation,
18:58
and so for the first time, we had 3D graphics,
19:01
the ability to rewind time,
19:03
sound, music, you know all these things
19:05
that the Apple II couldn't do,
19:06
but we still had constraints.
19:07
The first draft of the story for The Sands of Time
19:10
had been much more complicated with kind of
19:12
this political intrigue
19:13
and you know different factions within the kingdom,
19:16
so for the final game,
19:17
we ended up stripping all of that out,
19:20
and going with a much simpler story
19:21
in which everybody in the kingdom has been transformed
19:24
into sand monsters,
19:25
and that one decision made it possible to design a game
19:28
that was actually in sync with what you could do
19:30
with a controller in your hands
19:31
because everybody that you met was a sand monster,
19:33
so your only options really were acrobatics,
19:36
combat and running away,
19:38
and that was a good fit with what you could do as a player,
19:42
even though we had the ability to do dialog
19:44
and facial animations and so forth.
19:46
Having a large cast of characters would have taken
19:49
the game away from its strengths,
19:51
so in designing a game story,
19:52
you really want to plan choices that emphasize the strengths
19:56
rather than emphasizing the weaknesses.
20:00
This year is the 30th year anniversary
20:01
of the original Prince of Persia,
20:04
and a lot of what I've told you today
20:06
I remember thanks to the fact that I kept a journal,
20:08
so we're actually re-releasing these journals as a book
20:11
for Prince of Persia's 30th anniversary.
20:13
They're the journals that I kept at the time
20:14
as I was making the games,
20:16
so it's got all of the roller coasters,
20:17
of all the ups and downs of,
20:19
this game is going to be great,
20:20
this game is going to be a disaster,
20:22
and how do I solve this particular problem?
20:24
We've also illustrated the journals with screenshots
20:27
of the work in progress and sketches,
20:30
so it's been a lot of fun for me on this anniversary
20:33
to have a reason to go back
20:34
and look at those little journals again
20:36
which being in the '80s are mostly on pen and paper.