Welcome and good luck to you then!
I cannot give a comprehensive answer, since all games tend to be different. Instead, I will do my best to provide a few answers about defence.
- First of all, you may want to prevent the enemy from getting into your systems to begin with. It is made easier if you have few warppoints enabling ships to reach your systems. Defending at a warppoint (also called wormhole) allows you to strike first, while being in range of the enemy. It means you will be able to deal some damage to the invaders before they can do anything, and so they will have a harder time entering your systems.
To do so, you can deploy satellites over the wormhole (they aren't too reliable anywhere else though), fighters if you have researched this technology or your own ships. Fighters are fairly powerful early on, but are countered by Point Defence weapons, so you should add a few ships as well. If you do so, do not put the fighters and the ships in the same fleet, since it will rapidly deplete the supplies of the whole fleet.
Another way to deny them entrace is to put mines over the wormhole. Mines are powerful, but you can only put 100 mines at the same sector, and they are destroyed by Minesweepers. Most invading fleets will have enough minesweepers to destroy 100 mines, and so you should only use mines early on during the game.
- But fighting at your side of the wormhole will not be enough as the game goes on. There is a component that enables a ship to open a wormhole, which will bypass any defence you may have at your wormhole. So if you cannot hold the wormhole, you will have to protect your planets themselves.
Weapon platforms, fighters, ships and bases can be used for this purpose. The weapon platforms are rather cheap to build, and they are designed for defence, so they are probably your best bet for now. Do not forget that they have mounts (click on Weap Mount to see them), which slightly improve the damage done by the platform, and above all, its range and its accuracy. Weapon platforms are more accurate and have a longer range than ships, and so you can hope to attack them first.
Bases serve the same purpose as weapon platforms, but they are in space rather than on the planet itself. You will need a spaceyard to build a base, and they are much more expensive than weapon platforms, so they are not so commonly used to protect your planets. Lastly, mines are an effective way of defending your planets, but as before, most fleets will come with enough minesweepers to destroy any mine you might have deployed. (Obviously, fighters and ships can be used to protect a planet as well, but this is their usual role)
- When being on the defensive, another factor is very important: happiness. All your planets have an happiness level, which goes from Jubilant to Rioting. You should strive to keep your planets Jubilant, as it improves production by 20%. On the other hand, Rioting means that the planet does not produce anything, and cannot build anything at all.
Happiness is changed by events (such as building ships, colonising planets or signing treaties), and you can improve it by building the Urban Pacification Center (found under Psychology => Applied Political Science) and Troops. You will lose happiness if one of your planets is destroyed or captured, and so you need to keep your planets as happy as possible so that losing 10 planets will not make your other 90 planets riot. Because of this, even planets far away from the front can become useless because of rioting, and it may bring your Empire down more quickly than enemy fleets.
This does not qualify as defending your systems, but it matters as much, if not more, than repelling the enemy fleet. In fact, you can win a game if you cause massive riotings to the enemy, even if you are losing all your major battles against his fleets.
- Lastly, there are other ways to stop a fleet from getting into your systems, which usually involve breaking the logistics of the enemy:
* Stellar Manipulation III (found under Astrophysics) allows you to close wormholes via a component (whose name I have forgotten). If you can close the wormhole the enemy fleet is likely to use, they will not be able to get to your systems. As said above, Stellar Manipulation III also gives a component doing the reverse, so it only works if you have a technologic advantage.
* All fleets require supplies to move and to fire their weapons. If you can prevent the enemy fleet from getting new supplies, they will eventually exhaust their storage and will not be able to do much at all. Once again, Resupply V allows you to use the Quantum Reactor, which gives unlimited supplies, but this component is expensive to research.
The
Frequently Asked Questions thread also gives a lot of advice about the game, and would be a useful read if you haven't already done so. And what Primitive said is certainly the way to go with the game in general.
strategy & tactics
Linear Mode
