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Subject: Succeeding at Battlezone with TQM.

Date: Thu, 5 Aug 1999 20:42:17 -0400 (EDT)

From: Doug Jefferys <>


To: "''" <>


On Thu, 5 Aug 1999, Christopher X. Candreva wrote:

> On Thu, 5 Aug 1999, Clay Cowgill wrote:


> > Big difference though-- BZ gives you two big handles to reef on, and a

> > compelling reason to pull back on both hard (the cruise missiles).


> There's your problem -- drive INTO the missiles. You have less time

> to aim, but the missles have less time to serpentine around you. Pulling

> back is certain death. Apparently without the step -- litteraly. :-)


Damn, I love Battlezone.


<BRAG>Personal high score: 1,201,000.</BRAG>


<HUMBLEREMINDER>The world record is about 5.3 million.</HUMBLEREMINDER>


My ROM revision stops giving me supertanks from what appears to be a

random score between 700K and 800K.  The game switches back to regular

tanks from that point forward, but continues to place them in the "hard"

places and angles that it did with the supertanks.  Saucer hunting is

once again possible, but much harder than it was at the start of the



I used to think this was a bug, but since it comes at a random interval,

as opposed to a hardcoded 800,000 points, it may be intentional.  (Since

the player has mastered the game, give him back the slower, more time-

consuming target that he *hasn't* spent much time fighting...)


One thing that is a bug, albeit an extremely unlikely one:


I've used the Battlezone High Score save mod on my board set, and changed

a byte to save the top 9 high scores instead of the top 3 scores.  Since

the game displays one tank beside your score for every 100K, my high score

table fills the vector table; the "Extra tank at xxxxx and yyyyy points"

text flickers out midway through the message.  I consider this a "bug"

since it's possible, though by no means likely, that a unit that runs

24/7 (in an arcade with a lot of Battlezone experts :-) could conceivably

encounter this in the field.  It's similar to the "too many bonus ships

slow down the game" problem in Asteroids.


Hacks on my "one of these years" list:


1) Make it so that only 5 tanks are displayed beside high scores,

   regardless of how high the score is.  With that 5.3M world record

   game, the monitor was probably trying to draw a tank on the side

   of the cabinet :-)


2) Figure out where in the code it switches back from supertanks to

   regular tanks, in order to judge whether it's a bug or not.


3) Hack in a "turn-180-degrees" button.  I'd love to hide behind a

   cube, press this button, and watch a missile run away from me,

   or add a "jump-three-feet-to-the-left" button and admire a missile

   from the side :-)


Now to gameplay:


Missiles come at you in one of (a small number?  3-5?) different possible



All but two can be defeated trivially by *staying still* and rotating

your tank a little to the left of the spot in the sky where the missile

first appears.  The missile's final approach will be straight down

your gunsights.  The two "bad missile tracks" are relatively rare by



One missile track has the missile doing a hard turn from your right,

straight across to the left, and into you.  It seems to zigzag in

the horizontal direction a little more erratically early on in its

flight path.  It is best nailed (assuming you stop as soon as a

missile appears) by firing just as it's turning.  The bullet will

hit the missile side-on.  This missile track can be avoided by pushing

forward at just the right time during its horizontal move.


Another missile track appears to be very similar to the one above, and

kills by making a horizontal move and nailing you from the left side.

Unlike the missile above, you usually see the inside a corner of the

missile as it turns into you.


(This may simply be the same missile track as the "shoot it in the

side" missile, but seen from a tank that's been turned 15-20 degrees

to the left.)


Since I don't see either variation frequently, and since I can't see

where the missile "would have gone" on my "long-range kills", I'm

guessing that each of these types (or this type, if it's only one

track seen from a different angle) are more susceptible to the long-

range kill.


My missile strategy:


1) Stop when it shows up.  Turn slightly to the left.  Identify the

   missile shortly it hits the ground.  Choose between long-range or

   conventional kill.


2.1) Long-range kill:  Fire immediately and start backing up for a

     second shot.  Many of my "missed" first shots end up as either

     conventional kills, or "push forward and hope it misses you

     because you won't necessarily have a round ready in time for

     the side-kill type".


2.2) Conventional kill:  Don't move, just watch the missile come

     closer.  Fire on the last move forward to you where you can't

     miss, or nail it with a sideways kill for the one (or two?)

     missile tracks that have to be killed sideways.  Move forward

     when you fire; it won't hurt in the straight-in kills, and it

     might save your butt if you miss the sideways kill.


3) Set up for next kill.


   If you pulled back for any reason, move forward.  There may be a

   cube that's now six inches from your rear bumper that'll get you

   stuck when the next missile/tank appears.


   If you turned left, rotate right a bit.  Since each missile

   prompts a few degrees of left-rotate, you may end up with an

   obstacle in your field of view.


My general strategy:


1) The usual "run down the 45-degree line and kill" strategy.


2) Making sure there are no obstacles anywhere near you after each kill:


   The key to killing missiles is to make them predictable.  If you

   expect a missile to go one way, but it has to jump an obstacle or

   steer around it, you'll miss your shot and die.


   The key to killing tanks is *not* to get jammed up against an

   obstacle, ever, so you can make every kill a "conventional" one.


   The best way to do both of these things is to keep a mental map

   of where the nearest obstacles are likely to be, and to keep moving

   so that there's (a) nothing near you, and (b) if you haven't moved

   forward in a while, assume the computer's put an obstacle behind

   you and move forward to get away from it.


   (Yes, sometimes the computer sprinkles the ground with new objects.

   This is known as the "You trip over an imaginary invisible deceased

   turtle that a mad wizard teleported behind you" method of dying :)


3) Ingore saucers whenever there's a supertank on the screen.

   One potshot is allowed while rotating to kill the tank.  Do not

   stop turning or moving - just take the shot and hope for the best.

   Never chase saucers with supertanks on, because they move to give

   the supertanks a better shot at you.


   With missiles, it's similar - *one* shot at a saucer between

   missiles.  No more.  And don't attempt to get a long-range kill

   on a missile if you're taking potshots at the saucer.


These strategies will get you into the 300-500K level, maybe 800K if

you're lucky.  You'll also learn little tricks like seeing the fading

dot of a new tank *before* the radar sweep hits him and turning in his

direction before the "blip", or seeing the little nudge forward that

a tank will make just before it fires its first shot at you, and

being able to take evasive action before his bullet is on his way.


You'll most likely die by mis-identifying a missile, getting caught

by a new obstacle after a long missile-chase, or by trying to kill a

supertank on those semi-rare occasions where you miss your one shot

at a tank who's forced you to run away backwards while you wait for

him to shoot-and-miss.


For endurance play - do all this, and take steps to *not* get killed

by the "one-in-a-million dumb luck" things.  Like saucers appearing

directly in front of you when you're about to kill a missile, or the

tank that hit a pyramid, turned, backed up, and moved forward... and

did it again, only to be *facing you* when it stopped and fired while

you were rotating to keep up.  Like supertanks appearing right in front

of you, facing you - and knowing instantly whether you can kill it

immediately, or if you have to turn *away* from it and run away for

a second or two before killing it "conventionally".




OK, so what the hell does an old buzzword like Total Quality Management

(TQM) have to do with succeeding at Battlezone?


Battlezone is a great game if you've ever wondered why software QA

types are so picky about process and metrics.  There are only a few

ways to get killed in Battlezone, and nearly *every* death can be

explained in terms of "operator error" of one form or another.


Since you have only five tanks (3, plus one at 15K and one at 100K)

per game, the only way to get a score of "x" is to ensure that you

get, on average, "x/5" points per tank.


Furthermore, since Battlezone isn't a game of reflexes, the existence of a

world record at 5M is evidence that, at _worst_, the game only puts you in

"impossible" situations every million points or so.


The corollary of that is that *if you're getting less than a million

points per tank, you're probably making mistakes that you can prevent*.

Here's a partial list from the top of my head.  Only the last two items on

the list are "accidents"; the rest are variations on operator error:


- Rotated too long when turning to face enemy.

- Turned to face enemy, fired, and missed.

- Didn't run enemy down line of sight correctly, allowing him to kill me.

- Ran enemy down line of sight just fine, but pulled back too long before

  rotating.  By the time I got him in my sights, he fired at point-blank


- Chased saucer.

- Missed missile and died.

- Missed missile and didn't back up to get enough time for second shot.

- Missed missile and backed up, but hit obstacle and couldn't get far

  enough back for second shot.

- Obstacle in missile's path made missile move differently than expected.

- Thought it was different type of missile.

- Damn!  I _always_ seem to get killed by "that type of missile".

- Thought I had enough room in front of tank to kill it head-on.  Missed.

- Thought I had enough room in front of tank to kill it head-on.  Didn't.

- Didn't *listen* for enemy tank shooting at me while I took a

  potshot at the saucer.

- Didn't *listen closely enough* to hear enemy tank shooting at me

  within a few milliseconds of me shooting at the saucer.  Sounded

  a bit like an echo.

- Didn't *listen closely enough* to hear enemy tank shooting at me

  while saucer-exploding sound was playing loudly, mostly drowning

  out the noise of the enemy shot.

- Didn't *hear* enemy tank shooting at me because I fired _exactly_

  at the same time the enemy tank did and I _couldn't_ have heard it.

- Saucer was behind me and passed in front of me, covering 90% of

  the viewscreen just as I was about to shoot the missile.


Once I started "taking notes" on how I died, my game improved drastically,

as I was able to stop making the mistakes that kept killing me off every

50-100K points, which means that I now live long enough to get killed

every 200-300K points, usually by misidentifying a missile and firing

in the wrong portion of its flight.


And I still don't think I've ever had a "couldn't have heard the enemy

tank" kill in my life.  (Had plenty of the other variations, though!)


The "Saucer flew in front of me" death is truly rare.  It's happened to me

twice since I started playing Battlezone seriously, which means you can

expect it to happen once every 5 hours or so.


Interestingly - if you hear the "saucer died" sound without shooting the

saucer, it usually means an enemy tank has shot it.  This happens once

every half hour or so, but only in your field of view every 2-3 hours.

Sadly, you don't get the points for letting the enemy kill the saucer

for you.






 dougj   |

   @     | |


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