Rapidfire

The end of Ogame's beginning stages begins when Battlecruisers and Bombers start showing up. These expensive ships bring huge changes to the nature of the game (and introduce a huge number of tactical options).
Consider three defense bashes, to illustrate how powerful the rapidfire is, and equally how important it is to reduce the chances of rapidfire progressing.

Bash 1
25 Battleships vs 20 Rocket Launchers 100 Light Lasers 20 Heavy Lasers 10 Ion Cannons 3 Gauss Cannons and a small shield dome.

Bash 2
15 Battleships and 6 Bombers vs 20 Rocket Launchers 100 Light Lasers 20 Heavy Lasers 10 Ion Cannons 3 Gauss Cannons and a small shield dome (the same defense).

Bash 3
15 Battleships and 6 bombers vs 20 Rocket Launchers 50 Light Lasers 20 Heavy Lasers 10 Ion Cannons 3 Gauss Cannons and a small shield dome, but this time there are 25 Light Fighters instead of 50 of the LL (the defense has the same number of points).

Using drago-sim with no difference in tech levels, the first battle ends in a draw with most of the attacking fleet likely to be destroyed, the second ends in a likely victory for the attackers, and the third ends in similar smashing defeat for the attackers (even though their shots do far less damage than previously).

I wish a battle simulator showed the damage points inflicted by each item (for more complex battles), but since these only have two ships and the battleships can only shoot once every time you can see the change. On average, the bombers do 243,000 damage in 5 rounds while the battleships only can put up 65,000. Not bad considering the bombers cost substantially less than the remaining ships.

However, in the final battle, look at how much a few fighters (just 22% of the targets), but they greatly reduce the bombers' damage (enough that the defense draws rather than loses). The bombers on average take 3-4 shots per round rather than 10-11, and the total damaged is halved. More importantly because the defenses aren't being destroyed as quickly, they do substantially more damage to the attacking fleet. Even with just a few non-rapidfire ships (20% the chance of getting more than 3 shots drops to 50% (0.8x0.8x0.8).

The lessons are, especially when facing battlecruisers and bombers, have something in your fleet that they can't rapidfire, but remember it's numbers that matter. Since rapidfire ends if it strikes something that the ship doesn't have rapidfire against. Also, rapidfire can be exceedingly powerful especially when facing large numbers of ships that a single ship can rapidfire, but it's usefulness declines quickly when facing a fleet with even a little diversity.