Double your fire power
 Getting captured
One of the most interesting, unique, and useful features of Galaga is the tractor beam performed by the Boss Galagas. By doubling your firepower, this maneuver can give you the opportunity to achieve the maximum bonus in Challenging Stages. The entire sequence goes like this:
- You survive the entrance section.
- During mid-battle section, a Boss Galaga peels off and dives straight down in a markedly different pattern from the usual one-loop off the side.
- The Boss Galaga stops two inches above the bottom of the screen.
- A strange sound begins, and a fan shaped blue energy field emanates from the bottom of the Boss Galaga.
- If your Fighter is not in range of the beam up field, eventually it retracts and the Boss Galaga drops straight down to return to formation.
If your Fighter is in range, it is caught and whirled up to rest beneath the Boss Galaga. At that point, the message "FIGHTER CAPTURED" is displayed and the Boss Galaga returns to the top of the formation dragging your Fighter behind. A foreboding musical tune is played. If you have another Fighter, you begin playing with it. If you don't, the game is over. (Note: Never get captured when you're playing with your last Fighter.)
 Don't destroy yourself
Now one of your Fighters is in the enemy formation. If you shoot your own Fighter, you get 1,000 points, but lose the extra Fighter--you don't want to do this under any circumstances. Be very careful where you shoot when you have a captured Fighter in formation. For instance, you can shoot at an enemy to the side of a captured Fighter, have the Fighter and its escort swoop off and run right into your shot.
If you shoot the Boss Galaga that captured your Fighter while it is in formation, eventually the captured Fighter will swoop down on you. Don't destroy it. It will disappear off the bottom of the screen and go away. But all is not lost; it will reappear as the last ship to enter on the next entrance screen. Be very cautious about shooting at the last wave of aliens when they enter! Your captured Fighter will appear at the tag end, then take its place at the top of the formation. Some players use this as a expert's technique to store a captured Fighter.
 To the rescue
If your captured Fighter still has its Boss Galaga, it will eventually swoop down on you with its escort. It always follows the same pattern; it heads for one side or the other, with one loop in the middle. Be very patient, and do not try to hit the Boss Galaga in mid-flight; it is very easy to miss the enemy and hit your own Fighter! Wait until the Fighter is within an inch of the bottom, line up with it and hit the Boss Galaga exactly in the center.
If the Boss Galaga is green, you have to hit it twice to destroy it. If it is purple, you only need to hit it once. If you succeed in destroying the Boss Galaga, a marvelous thing happens, one of the greatest things about this game: your Fighter is freed and it joins your currently playing Fighter. Your firepower doubles.
 Now stay alive
For those who have a difficult time staying alive due to the increased target area of the Double Fighters, try getting the Double Fighters for only the Challenging Stages. For those who are used to it, get it as quickly as possible on Stage 1 and use it thereafter until at least Stage 12. If you have a Double Fighter and it gets destroyed by accident, restore it until Stage 12 or above. Is the increased target area a liability? No, it actually helps you stay alive, for not many enemy ships make it through the entrance stage if you use your doubleship to its fullest most ferocious capabilities.
Note that when you free a captured Fighter, any enemies in mid-dive will return to formation. While this is happening, you have a free shot at the whole formation. Your captured Fighter will be suspended in mid-space spinning. It is invulnerable to your shots at this point and can not be destroyed until it joins you. Pick off as many enemies as possible in the formation. The Double Fighter gives you more firepower than a single Fighter. Use it wisely and watch your score grow.
 Entrance patterns
The most important part of Galaga strategy is anticipation. In order to play effectively, you need to know where the enemies will appear and how they will move before they get there. This knowledge--combined with firepower of the Double Fighter--will allow you to finish each Stage quickly and efficiently.
The way that the enemies come onto the screen is called their entrance pattern, and the entrance pattern is always the same for a given Stage. There are three different entrance patterns. Before looking at the order they appear in, let's look at the features of each one.
First entrance pattern
The first entrance pattern is the most difficult because it is the only pattern where enemies will enter from both sides of the screen at the same time. The enemies enter single file in short rows. The best place to fire from in this entrance pattern is the center of the screen, where both sets of enemies will cross above you. This is also the safest place to be, because the enemies will drop bullets as they come onto the sides of the screen.
Second entrance pattern
In the second entrance pattern, the enemies enter from one side of the screen at a time in double-width rows. The first group will enter from the left, so position your ship one ship's width in from the left edge of the screen and wait for them.
Third entrance pattern
The third entrance pattern is similar to the second. The enemies enter from one side at a time, starting from the left. But instead of two rows moving together, they appear in a single long row. As in the second pattern, you should wait near the left edge of the screen for the first group of enemies.
After the start of each entrance pattern, the general strategy is always the same. Anticipate the entrance of each group, and kill as many of the enemies as possible before they move into formation. Then move across the screen under their bullets to get in position for the next group. Fire constantly as you move across the screen to clear out the enemies already in formation.
If you eliminate most of the enemies in each group before they reach the formation, there will only be a few bugs left after the last group as entered. You'll have to destroy these individually, but this is the only time you need to aim your shots.
In the first two Stages, you won't need to worry too much about entrance patterns because the enemies aren't very aggressive yet. Just try to acquire a Double Fighter so you'll have it going into the first Challenging Stage.
 Challenging Stage
A Challenging Stage comes after each set of three entrance patterns. The only exception to this is the first set, where the third entrance pattern is skipped. Stage 3 is the first Challenging Stage. After Stage 3, the set of four different Stages (entrance patterns 1, 2, and 3, and a Challenging Stage) repeats over and over.
At the start of the first Challenging Stage, position your ship in the exact center of the screen. To make sure you're centered, watch how your shots pass through the words HIGH SCORE at the top of the screen. If you're exactly centered, your left shot will pass through the last H in HIGH and your right shot will pass through the S in SCORE.
From this position, you should be able to get all of the enemies in the first Challenging Stage without moving. In fact, it is possible to shoot all of the enemies in this Stage just by holding the fire button down. If you miss any enemies, you'll get another chance to hit them when they retreat off the top of the screen. Move back to the center immediately after chasing any missed bugs, so you'll be ready for the next group.
The second Challenging Stage can also be cleared from the center of the screen. After that, the Challenging Stages require you to move around more. Each Challenging Stage has five groups of enemies, so there will be up to five different positions you must fire from. Once you have found a position that works for a given group of enemies in a given Challenging Stage, always return to that position for that group. Eventually, you will develop your own set of position for each Challenging Stage.
Starting with the second repeat of the entrance patterns (Stage 4, 5, and 6), special bonus enemies begin appearing. A Bee will begin pulsating and move out of formation to change into a short row of transforms. In Stages 4, 5, and 6, the transforms are yellow Scorpions, and shooting all three will earn you a 1,000 point bonus. In the next repeat of the entrance patterns, the transforms are the green Spy Ships from Bosconian, and a set of three is worth 2,000 points. The next repeat of the entrance pattern has Galaxian Flagships for transforms, and sets of three are worth 3,000 points. After that, the three different transforms repeat in the same order. Transforms are always worthwhile targets because they are not very aggressive and are worth more than the other enemies. However, the third set transforms very quickly, so be cautious about those.
 Secret: Disarm the bugs
The Galaga enemies can be made to stop firing for an entire game by the following trick. Shoot all of the enemies in a wave except for one or two of the Bees on the far left. You can leave either one or even both, but it is easier to leave just one, because your next task is to avoid the Bee's fire for up to 20 minutes without shooting them.
After you have waited long enough (anywhere from about five to 20 minutes), the Bee will stop firing. After it has passed through the top of the screen four times without firing, you can shoot it. From that point on, none of the enemies will fire at you again.
Avoiding the Bee's shots for 20 minutes can be difficult. One good technique is to stay in the far right corner most of the time. The only shot that can hit you there is one released by the Bee while he is off the screen momentarily when he wraps around. If you do get killed, you can just pick up where you left off.
After the Bees have stopped firing, the game is very easy. If you are careful to avoid the enemies that scroll off the bottom of the screen, you should be able to last indefinitely. If you're in a two-player game, the first player can do the trick and enemies will not fire on the second player's turns either. But after the first player has lost his last turn, the second player's enemies will resume firing.
 Wave 256
Depending on the setting in the arcade. The game acts differently at this point.
The 1981 arcade game, Galaga has a kill screen that players encounter if they should pass stage 255. The counter for the level variable wraps around to zero and causes unexpected behavior when stage 0 is played. What happens on this kill screen depends on the difficulty setting of the machine. On the easy skill, the game resets. On the medium skill, stage 0 plays as a strange cross between the second challenging stage and a regular level where the enemies shoot. On the hard skill, the words "Stage 0" stay on the screen forever and no more enemies ever appear. On the hardest skill, stage 0 plays like stage 1, but it is still as difficult as stage 255.
On the NES version, after stage 200, it stops showing medals for the stages and reverts to a counter that continues to show levels (possibly up to 999).
On the XBOX 360 Live arcade version, they have fixed the bug, and the last playable level is 255.After that you are returned to level 1, with the gameplay back to its original speed.
 Scoring in the millions
Only on the second player do the digits show the millions place in the arcade version. The first player score only shows six digits and flips back to 0.