Defenses the combat model

The ship descriptions leave much to be desired, and I'm not sure they fully include the impacts of rapidfire. Especially for the bomber and battle cruiser, rapidfire is the only reason to use these ships. Lacking rapid fire, the more expensive destroyer serves a very different role.

Let's look at the defense installations first:

Rocket Launcher--Simple and Cheap
Description:
These are the first installation you can build. With it's 200 hit points and 20 point shield, these can not take much damage and their 80 damage points do not send ship captains knees to quaking. A major early disadvantage is they are vulerable to cruiser rapid fire.

Adam's Take:
Use these early to protect your mine profits from early raids, since they require almost no research and don't slow your mine building down. After that they don't cost much less than light lasers, and are less effective.

Light Laser--Your basic defense fodder
Description:
The next defensive installation. Laser beams designed to knock fighters out of the air and keep small raiders at bay. In large numbers they can cause larger fleets some pain, but need adequate support to fight capital ships.

Adam's Take
They are much more effective and make good fodder. In simulations with mixed light fighter, heavy fighter, cruiser fleets these will destroy nearly 2x the attackers. They remain more effective than the same resources spent on rocket launchers and ion cannons. There are few defensive resources that are as effectively spent as these.

Heavy Laser--Take the little one and let boys be boys.
A larger laser weapon. These get very mixed reviews with some making them the core of their defense and others deciding they are quite ineffective.

Adam's Take
With an improvement in structure and shields, but only a modest improvement in weapon power, these become useful when facing larger numbers of heavy fighters that your light lasers don't destroy in a short battle. Especially if you have a technical advantage (4 more weapon tech levels than the attacker's armor level). It's probably worth mixing a few in, but most of the time the 4 light lasers will do more damage (more light lasers will be destroyed in the smaller battles, however).

Ion Cannons--Mini shield generators
These cost a fortune in precious crystal, but have a very important purpose. They have very high shields and can soak lots of shots from the smaller ships.

Adam's Take
I know that crystal is dear in the research phase, so save these for the end (after you've researched hyperspace engines and battleships). These are the least used defensive installation, but they easily exceed the value of the much more frequently used shield generators (sim out a variety of attacking fleets and see if any defensive installation doesn't improve if the shield generator is replaced by an ion cannon and 4 light lasers. I prefer them later in the game to counter large fleets of escorts. Get these and some light lasers instead of that shield generator, since a shield generator can only absorb a very small portion of attacks (until the battle is down to the last few defensive units, but it's likely lost by then anyway).

Gauss Cannons--The first truely big gun
These are the first defensive installation that strikes terror in the hearts of attacking captians. Importantly nothing has rapidfire against these until death stars arrive, so they have staying power.

Adam's Take
Expensive but these have the offensive power of a battleship and they make up the core of a good defensive installation. Adding ten of these to your defense portfolio and everyone but the largest empires probably won't even consider attacking. Requires a large number of battleships or other capital ships to destroy. Make sure they have lots of additional targets, probably 8-10x as many light lasers and a decent number of ion cannons and/or heavy lasers to draw hits away from them.

Plasma Turrets--"Bring my brown pants"
Able to hold off death stars and bring them down with some support. These are the ultimate defensive installation. No rapidfire gives your defenses a break from a huge bomber or death star's rain of fire.

Adam's Take
Defensive excellence, but their cost and lack of rapid fire against attackers means that they should be suplimented with lots of gauss cannons and things to pick off and absorb hits from the attacking fodder.

Shield Generators
A big shield.

Adam's Take
Waste of all that crystal. Would be wonderful if they somehow added to the shields of your defensive structures or provided a planetary shield, but they don't so with OGame's combat model, they will only absorb a small fraction of the shots. They'll last a long time, will prove little more than an annoyance to attacking fleets that could defeat the other defense. Invest the resources you would have put in shield generators, in more ion cannons and light lasers which will draw many times more shots.

When raiding, I love seeing shield generators in the spy report because it usually means the planet won't be as well protected a similarly ranked planet without them.


So there's the run down of the defensive installations. At first you'll want a rocket launcher or two to keep those solo cargos from raiding you. Soon after you'll want to invest the resources in small lasers. Then push to Gauss Cannons and finally adding Ion Cannons and Plasma Turrets to the mix, and you'll be well on your way to turtle power (or at least unmolested mines). Miners who spend their generation regularly don't make good targets with regular investments in defenses. Your goal should always be to invest enough that the nearby raiders don't scout you after a few days of looking. Once they see you're not a profitable target they'll hunt for greener pastures in the early game. Later you'll be a target if you become a turtle, but by then you should be able to take care of yourself.