Base Defense Guide

This site belongs to Merovech, formerly of Ceti; now resident of Epsilon.

  The Base Defense Guide describes suitable defenses premised on the base's economic impact. The goal is to provide a basic understanding of base defense that enables a player to build defenses specific to his needs. Remember, any base defense may be taken by a motivated rival. The objective is to reduce the benefit the rival gains by taking the base.

While Patton's famous saying is valid, in Astro Empires the only thing more foolhardy than fixed fortifications is no fixed fortification. Astro Empires is an economic, military, political simulation. To ignore any of these aspects is to jeopardize one's enjoyment of the game. This guide discusses the defensive structures and offers a structure for when to have what mode of base defense.

Motivation

As with the Small Fleet Doctrine, this guide is about efficiencies. You are trying to raise the efficiency of your defenses to reduce the efficiency of your rivals. If he is going to take your base, you need to ensure he does not profit in the exchange. Generally, wise rivals only attack bases that are likely to turn a profit. The question becomes what is profit? Defenses generally deter those who are after momentary financial gain. Some rivals have other motives: power, shame, control and the strategic goal of suppressing an opponent in war are other reasons why a rival might hit your base. To defend against these motives, a player's only real defense is a strong mobile fleet that he closely shepherds. That mobile fleet is the purpose of the Small Fleet Doctrine.

There are essentially three things your base defenses protect. The obvious first benefactor is the base itself: its economy and productivity. The second benefactor is that base's trade. The other benefactor is the fleet in orbit over that base.

Strategy

The power of a base's combined defenses and fleets should exceed the total economic value of the base, fleet debris and trade routes. The defenses protect the base and the fleet protects itself and the trade routes. How do you calculate the base's economic value?

• The value of the fleet debris is twice the percentage of the player's Armour technology. Therfore, Armour-12 provides 24 percent that fleet's value of debris.
• The trade routes are a simple addition of the value of the route viewed in your base's Trade tab.

The economic value of the base is a little more fluid. The value is:

That is, divide the total imperial economy by that base's economy; this is a percentage of its contribution to the economy. This provides a percentage share of the credits you have available to spend.¹ To this, you add the pillage bonus. The table below shows the rough bonus provided derived from that base's economy. I would argue that the bonus is what pillagers can rely on, so discount the cash-on-hand benefit by keeping those credits banked or spent.

To protect the trade routes, you need an efficient fleet (a balance of Fighters and Cruisers) overhead. To keep it simple, let us assume that the fleet's responsibility is to defend itself and the trade routes, and the base defenses are responsible for defending the base. When you get to Planetary Rings, you will learn this model starts to flake as the defenses are strong enough to assist in protecting the value of the trade routes.

[url='http://espacesociety.org/AstroEmpires.BaseDefenseGuide#pillagebonus']#pillagebonus [/url]

Example

Assume you have 7000 credits on hand, your total economy is 1000 and your base's economy is 100. The percentage share is 10 percent (1000/100), or 700. The pillage bonus is 5400. Therfore, the rival would obtain 6100 in pillaging that base.

Continuing with the example above, if you have 10,000 credits in fleet over the base and your Armour technology is at level 10, then that fleet would provide 2,000 credits in salvage. Therefore, the base's fleet and pillage value is 8,100.

If your base has four trade routes each valued at, say, 2000, then the piracy value is 8,000. Therefore, the economic gain to your rival is 16,100.

Finally, you have to deduce how much salvage he may obtain in recovering his own fleet. Assuming his fleet was evenly matched with yours (10,000) and had the same Armour tech, then he would recover 2,000. This makes the total economic value at 18,100. '''Your defenses must create more economic loss than 18,100 to make that base non-profitable.''' Based on the rule of thumb above, your base defenses need to handle 9,000 credits of this value, with the overhead fleet able to handle the other 9,000 credits (or more).

Let us assume your fleet defenses are a split mix of Cruisers and Fighters (5,000 or 25 Cruisers and 5,000 or 1,000 Fighters). Assuming power technology (Laser and Plasma) at 10, then the combined firepower of this fleet is 39,000; but you have to be mindful of the weakness of Fighters against shielded units, which reduces the overall effecacy of the fleet. In the face of Dreadnaughts, the Fighters and Cruisers are effectively worthless.² What can we do to even the odds?

First, the solution is not always more fleet. More fleet equals more debris. So, the fleet becomes its own problem. This is why the base defenses should be somewhat self-sustaining.

Defenses

This section discusses the four categories of Base Defenses. For the purpose of this article, Commanders are not considered.

Command Centers (CC)

Each Command Center boosts your overall defensive power by five percent. Veterans will build ten to fifteen CCs on a base to improve the power of the defensive fleet up to 75 percent. Building ten is considered reasonable for a free player. A Heavy Cruiser with 10 CCs and medium plasma research (10-15 levels) will dish out 125 points of damage. Command Centers protect the overhead fleet, which protects trade routes.

In the example above, the Cruisers delivered only 36 points, six after passing through the shield. With 10 Command Centers, they would deliver 54 points, or 24 points. That is four times more effective damage. Fifteen Centers would allow 33 points to penetrate the shields. So, instead of needing 128 Cruisers (25,600cr) to defeat a rival Dreadnought, you need 35 (7,000) or 32 (6,400) respectively. This improvement makes the Cruisers viable against Dreadnaughts (but not against Titans). So, do not underestimate the value of Command Centers.

Turrets

This guide groups Turrets together. They do not benefit from Command Centers. When you look at the destructive value of Turrets, you discover they are weak. In the beginning of your empire (before Level 20) Unshielded Turrets, Ion Turrets and Photon Turrets are of some utility. The rule of thumb is three of your best turrets, and always scrap the weaker turrets. You need the space for other structures. Weaker turrets can undermine the value of the higher turrets. You will notice, however, that Turrets have limits.

For example, the Photon Turret delivers 480 points per structure, or 1,440 at the Three-Turret Rule. That is suitable for bases with a value of 2,900. Based on the table above, this is a base with an Econ of 70 or less; assuming the fleet can protect the trade routes.³

By contrast, Disrupter Turrets provide 11,520, which handles a base economy of 150. Many Veteran players recommend that bases not exceed that economy until you attain Planetary Rings. Keeping the economy under 100 is what I would recommend.

Unshielded Turrets are useful only when the player is threatened primarily by Destroyers, Corvettes and Fighters. They are built in the early days of the Empire, then quickly upgraded to Photon and Disruptor. Ion Turrets have value in their sheild penetrability, able to place 510 power against shielded units.

Shields

Planetary Shields, and the lesser cousin the Deflection Shields, provide a measure of protection for your turrets and Planetary Rings. Shields regenerate the defenses (turrets and rings) when an attack does not destroy them. The amount of regeneration is based on a percentage of the remaining defensive strength. Fortunately, the battle report has two values that help with this calculation: “Start Defenses” and “End Defenses.” To calculate regeneration, multiply the original defensive level by the End Defenses percentage (e.g. Defense * .65 for a End Defenses of 65 percent). End Defenses are calculated based on the sum of armour present at the end of the battle divided by the sum of the full-strength armor.

Real Combat Example

This is best shown than explained. The following tables show an actual battle series.

Notice the starting value of the defenses in the second wave. You will also see one reason for demolishing your lower-level turrets. Watch the difference in the End Quantity of the Disruptor Turrets in the first wave with the Start Quantity of the second wave.

The third wave again demonstrates that the previous wave's End Defenses percentage is used to calculate the start defenses for the next wave.

Therefore, Shields allow your base to fight longer than it might otherwise be able. Because the shields have the highest armour, their remaining armour regenerates the armour of the Plantary Rings and various Turrets. There is a consequence to this.

Impact of Weaker Defenses

The weaker turrets drain the larger turrets because their start and end armour values are used to calculate the change in defenses; lowering the final result. Because they are more easily hit, they are always reduced to zero.

In the series above, the attacker was able to use Fighters, Corvettes and Destroyers, all of which would have been combat ineffective against the Disruptor Turret, but they were quite effective against the weaker turrets. Because of the weaker turrets, an attacker can whittle away the strength of the Disrupter Turrets simply by leveling the Photon Turrets.

The Photon Turrets above are seven percent of the total defensive strength; Ion and Photon Turrets together represent 11 percent. So with each successive wave, the attacker's weaker units could reduce the effectiveness of the more powerful turrets by 11 percent by reducing the weaker ones; even if they could not scratch the larger ones.

What lesson can we learn from this? When you have Planetary Rings and Disruptor Turrets, the weaker shields (12.8 verse 19.2) of the Turrets would make the Planetary Rings vicariously vulnerable to weaker units. Therefore, when you have Planetary Rings, remove all Turrets.

Have More Than Just Planetary Shields

Having the Planetary Shield as your only defense is also unwise. With the weak power in a Pshield, if it is your only defense, a single, patient Heavy Cruiser could effectively reduce your defenses piecemeal. Therefore, it is important to always have another base defense built in conjunction with the Shields.

Planetary Rings

Planetary Rings are the first true deterrant to capital ships. A bank of Prings delivers 15,360 points of Photonic trouble to any attacker.⁴

Following the Three Rule of Thumb, you should seek to have three levels of Planetary Rings, which delivers 15,360 points. Against a Death Star, it would inflict 14,790 power. Three sets would deliver 44,370 power, able to take down a Death Star, three Levis, ten Titans, or 85 Cruisers.⁵ The point is that a Planetary Ring is sufficent to defend a combined base value of over 40,000 credits.

“Pringles” is a term for a pair of Prings and Pshields. When you finish a set of Pringles, then you can start downsizing your defensive fleet. Or, more accurately, you can get those lazy bums into the attack. With Pringles-2, you can usually drop your defenses down to about 4000 FT and 2 BB.

Practical Example

Merovech recently tested the ability of an empire to dedicate its resources to producing Prings. At the time of this writing, the account is 66 days old, and all bases have Deflection Shields. The first base will have Planetary Rings at Day-69 of that account.

To attain this level, Merovech rigidly adhered to the principle of staying below Level-30. This limited the “overhead” threat of higher level players, but left him somewhat vulnerable. He avoided Disruptor Turrets, which encouraged three bases to be hit during this timeframe.

To remain below Level-30 your combined economy (times 100), fleet and technology must be less than 810,000.

With all technology required for Planetary Rings, Merovech had less than 340,000 technology. He kept his fleet to under 150,000. Under this formula, he needed to keep his economy under 3,200. He could have doubled his fleet to 300,000 and kept his economy under 2,100 and stayed below Level-30. However, this would have left him vulnerable to Levels above 37, which geometrically increased his vulnerability. So, at Level-27, Merovech started building five of the ten necessary Planetary Rings to defend his bases.

Each base met or slightly exceded the minimum construction goals of the Advanced Base Guide, with a 19:15:9:2 MR:RF:NF:AF production structures ratio. The bases also had Command Centers-10, and in many cases Spaceports-15.

[url='http://espacesociety.org/AstroEmpires.BaseDefenseGuide#standards']#standards [/url]

Standards

This section offers a suggested set of personal standards the player should strive to. The fundamental goal is to ensure you have enough defenses to deter a profit-seeker, and enough fleet to protect the trade routes.

Command Centers

The table below offers standards for Command Centers based on economy. The goal is to boost your defensive fleet's power to reduce your rival's ability to take your trade routes. At base essentially increases its economy by 20 percent per trade route, so the requirement follows. The Metal Refinery column is for those who like to balance their structure builds. The cost of that level of Refinery is approximate to the level of Command Center.

Turrets and Prings

The table below illustrates the relative value of structures and the economy they may be able to protect, based on the power delivered and the pillage bonus of the base.⁶ When considering these defenses, you must remain aware of the efficiency of larger units (e.g. Battleships) against defenses and adjust accordingly.

Shields

The rule for shields is easy. When you have researched enough for Deflection shields, build one level. When you have researched Plantary Shields, you build one level per level of Planetary Rings. Disband the Deflection Shields when the first Plantary Shield is built.

Fleet

Fleet size derives its value from the cost of the trade routes in a split ratio of 50:50 FT:CR. When you are dealing with capital ships, the ratio becomes 35:35:30 FT:CR:BB. Combined with the Command Centers, this keeps the derb value of the fleet down. More experienced players hit bases for the value of the fleet derbs, not the TRs.

Conclusion

To have adequate defenses, the player needs to ensure they have a balance of fleet, command centers and base defenses. The fleet protects itself and the trade routes and benefits from the Command Centers. The base defenses should be able to offset the pillage bonus, plus a ratio of the cash-in-hand. With this model followed, a base is an inefficent target, but is still vulnerable to a motivated rival. This guide seeks to inform the player in an approach to analyzing base defenses, but expects the player to adjust to his specific needs. This guide further seeks to show the player that Astro Empires is a bean-counting endeavor, and that taking time to look at the underlying structure helps find efficient ways to play the game.