Defender, Chapter 9: Free Space

Defender, Chapter 9: Free Space
NOTE: portions of this chapter were published in a Winning Edge column in JoyStik Magazine, November 1982.

The loss of all ten humanoids brings on Defender’s biggest challenge – a sea of quivering, firing mutants, along with up to four pods and a handful of bombers, collectively know as free space.  Although this challenge is at first an impasse, conscientious practice can make free space a mere inconvenience, if that.  Mastering free space not only eliminates its immediate threat, but allows a wider choice of strategies during normal play.  For example, the most efficient strategy discussed in Chapter 10 is also the one with the greatest risk of entering free space; consequently, only competent free space players can use it safely.

Since you will always enter free space at some point in the middle of a wave, let’s look at how to finish a wave of free space and then how to start one.  All of the following discussion assumes that you have entered free space on wave 4 or beyond. For waves 1 through 3 the same observations apply, but bombing the pods is not as important because there are fewer of them.

Going into space

As soon as you realize that you’re about to go into free space, take a look around and memorize what opponents are left in the current wave.  Even though you’ll be seeing them all soon enough, knowing what’s left as soon as possible gives you more time to plan your attack.  Your first actions in free space will be determined by how many mutants there are, so pay particular attention to how many landers were left in the attack wave; they will all become mutants in free space.

Another good thing to keep track of when going into free space is where your ship is relative to the mutant and swarmer reverse lines.  In particular, make a mental note of which direction you’ll need to fly to get to the mutant reverse line as quickly as possible.

If you run into an opponent, bullet, or mine at the instant your last man is mutating, you’ll start the next turn with that last man still alive and on the ground.  The move into free space isn’t final if it occurs after you’ve run into something, even if you see the man mutate and the planet shatter.

Finishing the current wave

When there are fewer than ten mutants left in a wave of free space, you can stay in one place and let them come to you, strafing or using the quick reverse to destroy them as they arrive.  When there are this few of them, get rid of the mutants before going to work on swarmers of bombers,  If there are intact pods left, don’t break them up until you’ve destroyed any nearby mutants; swarmers and mutants are a difficult combination, and best avoided when you have a choice.

With more than ten mutants, a smart bomb may be in order,  Use you own judgment to decide whether there are more mutants than you can handle without a bomb.  If the mutants are very spread out, you can often just use the mutant quick reverse on them one or two at a time.

If you decide to use a bomb on the mutants, you don’t have to do it right away; it’s a good idea to get rid of swarmers and bombers first, so that you wont run into them while compressing and bombing the mutants.  This is where your close attention to the position of the mutant reverse line when you entered free space pays off.  (You do remember where the mutant reverse line was, don’t you?)

Playing the mutant reverse line

The technique used to avoid mutants while shooting bombers and swarmers in free space is called playing the reverse line, because you simply stay near the mutant reverse line and use its power over the mutants to keep them at bay while dealing with swarmers and bombers.  When the mutants get too close on the left, cross over to the right side of the line to send them scurrying away.  After they begin approaching on the right, cross back to the left side.  Because the swarmer reverse line is far away from the mutant reverse line, you never cross it, and any swarmers left in the wave come directly to you.  Bombers, who ignore all this nonsense about reverse lines, will also come directly to you.  Even pods will slowly drift by if you wait at the reverse line long enough.

Playing the reverse line works best when all of the mutants are clustered in a small area.  If the mutants are very spread out, the nearest one to the left or right comes onto the screen so quickly that you must cross the reverse line very often, and this cuts down on your mobility for shooting the swarmers and bombers.  When this happens, you’ll want to pass through the mutants at least once to compress them, as described in Chapter 4.  Consequently, you may not always want to take the shortest path to the reverse line.  By intentionally going the long way around, you can pass through all of the mutants and cluster them tightly before you even get to the reverse line.

Finding the reverse line

“Wait a  minute,” you say. “I forgot where the reverse line was.”  This is a common problem; in fact, you’re the exception rather than the rule if you remembered where it was when you went into free space.

When you lose track of the reverse line, you have to go looking for it.  To do this, fly into either the right or the left and watch the mutants closely.  As soon as they all turn around, you’ve just crossed the reverse line.

Needless to say, it can be very difficult to fly around looking for the reverse line with a big, dark, angry cloud of mutants on your tail – that’s why you should remember to watch the reverse line when you go into free space.  If you get blown up during a wave of free space, remember that the reverse line will always be at the far edge of the radar screen when you reappear (just as if the terrain were still there).

Swarmers and the mutant reverse line

Shooting swarmers while playing the reverse line is different from shooting swarmers in most other situations.  The safest way to shoot swarmers, the follow move, will usually bring you too far from the reverse line and into trouble with the mutants.  The only way to stay reasonably close to the mutant reverse line while shooting swarmers is to use the more risky aerial dogfight method described in Chapter 5.  With a little practice, you’ll be able to time your reverses in the dogfight so that each pass brings you over the reverse line.

Breaking a pod while playing the reverse line is also tricky.  Aim the pod (see Chapter 5) towards the reverse line so that you can start the dogfight in the right rhythm, passing over the reverse line when you pass through the swarmers.

Bombing the mutants

If it seems like we’ve forgotten the mutants, that’s the purpose of playing the reverse line – it lets you forget about them.  Of course, you still have to get rid of the mutants to finish the attack wave.  After clearing out all of the swarmers and bombers, fly into the mutants and bomb them, as described in Chapter 4.  If they are already clustered, one bomb might get them all.  If not, you can either bomb as many as possible and shoot the rest, or pass through them once to compress them before bombing.

Playing the swarmer reverse line

Reverse line play also will work for swarmers, but the position of the reverse line is different (see Chapter 5 for the location of the swarmer reverse line).  When there are many swarmers and few mutants left in a wave of free space, play the swarmer reverse line instead of the mutant reverse line.  This situation is not common, since the mutants are the biggest problem in free space.

Starting a wave

Now that we know how to finish a wave of free space, it’s time to look at how to start one.  Ideally, we want an approach that will consistently finish waves of free space with the minimum risk, only using one bomb per wave.  A wave of free space is always worth over 10,000 points, so using one bomb per wave allows you to maintain a constant supply of smart bombs, because you will earn another smart bomb for finishing each wave.

At the start of an attack wave in free space, all 20 mutants appear on the scanner at the same time, rather than appearing in groups of five like landers in a normal attack wave.  The mutants are randomly positioned, but pods and bombers appear in the same places as a normal wave: bombers at the far edge of the screen, and pods just in front of your ship.  The mutant and swarmer reverse lines are also positioned normally: the swarmer reverse line is just behind your ship, and the mutant reverse line is at the far edge of the scanner.  Of course, the planet’s terrain is no longer available as a handy point of reference, so once you start moving you won’t know exactly where either line is until you cross it and see its effect.

The two bomb approach

One strategy for free space is to bomb the pods immediately, along any mutants that are on the screen.  By waiting a second or two before bombing, you can get many of the mutants to come onto the screen.  After using the smart bomb, go through the mutants that are left until you get to the mutant reverse line, then play the reverse line until all of the swarmers and bombers are gone.  One more bomb for the remaining mutants, and the wave is finished.

This approach is both easy to understand and easy to use.  Its biggest drawback is that it uses two bombs per wave.  If you want to use this strategy for free space, then, you must have a healthy supply of extra bombs.  If you only have one bomb left, and are going to use this approach anyway, make sure that bombing the pods (up to 8000 points) will earn you another ship and bomb; otherwise, you can end up with many mutants at the end of the wave, and no bomb with which to destroy them.

One bomb for the mutants

The next free space strategy uses one bomb for all of the mutants.  In order to do this, you pass through all of them twice to compress them.  When your ship first appears, fly through fly through the mutants to the right.  After you pass the reverse line, and the mutants behind you turn and flee, just continue moving to right, entering the swarm of mutants again from the left.  At this point, the mutants will be clustered very tightly.  Reverse and hit the bomb.  (The reverse is to avoid the mutants’ bullets, as explained in Chapter 4, under “Bombing Mutants”.)

With this strategy, you will never have more than three or four mutants left after bombing.  In addition, if you passed through the mutants quickly enough, the pods won’t have spread out and may have been victims of the smart bomb.  This, however, rarely happens, because it is very difficult to survive a pass through all of the mutants at top speed.

The best feature of the free space strategy is that it can get all of the mutants with a single smart bomb.  The bad points are that you usually won’t get the pods with the bomb, and passing through all the mutants is very dangerous.  Therefore, this strategy should only be used by players that have trouble shooting mutants and want to eliminate all of them immediately.  (Although, if you can successfully pass through the mutants twice to compress them, you obviously have the flying skills necessary to shoot mutants.)

One bomb for everything

The third strategy for free space is safer than the second one and more effective than the first.  It offers the best compromise for most players.  One bomb is used for the pods and mutants, as in the first strategy, but a subtle preparatory move draws nearly all of the mutants onto the screen before bombing.  This move takes advantage of the fact that your ship appears on the screen, fully capable of flying, a full second before any of your opponents appear.

During this second of time, reverse and move to the left while rising up to the top of the screen.  At the instant the mutants, pods, and bombers appear, reverse again and fly to the right, pulling down and strafing the mutants.  When you reach the pods, reverse again and pull up, waiting as long as possible before bombing.  This bomb should destroy all of the pods and almost all of the mutants.

As soon as the bomb goes off, turn again and fly to the right to play the mutant reverse line and finish off the wave.  You will always pass two or three bombers moving to the left on your way to the reverse line (unless the smart bomb got them), and it helps to shoot them as you pass; otherwise, you’ll have to wait at the reverse line to come all of the way around again.  You won’t have time to stop to shoot them, however, since all of the mutants that survived the bomb will be following close behind you.

If you’re good at shooting mutants head-on, an even better course of action after the smart bomb is to fly to the left and finish off the remaining mutants.  Fly along the top edge of the screen, shooting the mutants as they appear there.  This will help you finish the wave a little faster, but it is more difficult than going to the right and playing the mutant reverse line.

Another adjustment for hot players is to wait at the top of the screen when you first fly to the left, before the opponents appear.  Then, as soon as you can see where the mutants are, decide (1) where the best opening is to pass through them, and (2) how long to wait before making your move; if the mutants are mostly to the right of the pods, you should wait a little longer than normal before flying into them.  This will bring more of the mutants onto the screen when you smart bomb.

When all the pods and swarmers are on the screen, the smart bomb doesn’t always destroy everything.  Many opponents may hyper away while the bomb is going off, and these will show up alive and well on the far edge of the scanner.  When you see this happening – you can actually see the mutants and pods hypering away during the bomb – try hitting hyperspace.  If you’re successfully moved to another part of the scanner, the hypering will stop and all of the remaining opponents will be destroyed.

Obviously, this last free space technique is more complicated than the others; it will help to reread the preceding paragraphs several times before trying it for the first time.  Its benefits, however, justify the extra trouble it takes to learn.  The only way to make one smart bomb count more in free space is to use the risky second method above and be very good or very lucky or (most likely) both.

The shot timer

Sometimes, when starting a wave in free space, you’ll notice that none of the mutants are shooting at you.  At the start of any wave, none of the opponents fire for a random length of time, just to give you a chance to get started.  Although the shot timer is beyond your control, you can take advantage of it when you notice it’s set longer than normal by waiting as long as possible before bombing the mutants, knowing that you won’t have to worry about dodging their shots after the bomb goes off.

Surviving the smart bomb

Regardless of which free space strategy you decide to use, you’ll probably have trouble surviving the smart bomb at first.  The smart bomb itself doesn’t blow up your ship, of course – it’s usually one of the mutants’ bullets, which stay on the screen for a short while after the bomb.  Because of the explosions caused by the bomb, these bullets are very difficult to see.  To consistently survive bombing large groups of mutants, then, you’ll need to get in the habit of concentrating on the bullets on the main screen whenever you use a smart bomb.  You can usually tell the bullets from the explosions by their motion – the bullets are traveling in many random directions, while the explosions generate flashes of light that radiate in star-like patterns.

After you’re able to tell the difference between debris generated by the smart bomb and bullets, it will usually be obvious immediately before the bomb goes off whether you’re going to survive.  If you see there is no path through the bullets on the screen, hit hyperspace immediately after the smart bomb goes off.  Always be prepared to abandon your plans and use hyperspace when it’s obvious that you aren’t going to survive; if you use hyperspace wisely, there are no impossible situations in the game of Defender, only situations where you must accept hyperspace’s 75% chance of survival.

Space without bombs

So far, we’ve been assuming that you always have at least one smart bomb to use in clearing a wave of free space.  But sooner or later, you’re going to find yourself starting a wave of free space without any smart bombs left.  This is an overwhelming situation; most players just start shooting pods as soon as they appear, in a frantic effort to earn another bomb, which will quickly be wasted on the mutants, bombers, and (now) swarmers that make up the attack wave.

Believe it or not, there is a fairly successful way to play a wave of free space without a smart bomb.  Instead of panicking and going after the pods, turn to the left as soon as you appear and strafe your way to the mutant reverse line.  There will only be a few mutants between your ship and the line, and it’s important to shoot these on the way there.  This guarantees you enough room to play the reverse line effectively.

When you cross the reverse line, keep moving to the left and shoot the nearest pod.  Then follow the swarmers back over the line, shooting all of them as quickly as possible.  After crossing back to the right side of the reverse line, you’ll meet an approaching squad of bombers; clean them up quickly and turn to meet the other squad, approaching from the left.  After you’ve finished off all of the bombers, play the reverse line until you get a chance to shoot the other three pods, one at a time, and shoot all of the swarmers.  All that will be left then is the mutants – several strafing runs will take care of them.  Or if you’ve earned a bomb while shooting the pods and bombers, you can use it on the mutants.