Taxation
Overview
Taxation is the process in which you raise megacredits. You can tax colonists or (if any) natives. Amorphous natives do not pay taxes. There are two commonly used taxation practices. A combined maximum of 5000 megacredits may be raised per planet per turn. Cyborg colonies can collect megacredits from a maximum of 20% taxes on the natives.
Taxation slows the growth so dramatically that it is not always wise to tax. If you cannot get a lot of megacredits from taxing, then it is usually better to not tax at well as long as the population is still able to grow. Even 1% taxes slows growth to 5/6.
Safe Taxing
Safe taxing employs a constant taxation which allows megacredits to be raised every turn without decreasing happiness. As a general rule, this is not recommended, except in situations where the population cannot grow any further due to climate conditions.
Growth Taxing
Growth taxing employs spikes in taxation. On one turn, a lot of taxing can be done while no taxes are employed on subsequent turns to maximize growth. This has the risk of accidentally causing riots and civil wars if this is left unchanged due to the dramastic change in happiness this imposes.
Calculations
The base formula for the amount of money raised is as follows, where r is the tax rate, p is population, and g is the government modifier (for colonists, g = 100):
The amount of megacredits that may be collected from natives is capped by the number of colonist clans present at a ratio of 1:1. Then bonuses from the The Solar Federation and Insectoids are applied multiplicatively (meaning that Feds taxing an Insectoid planet get 4x the money). Despite these bonuses, the final cap is still 5000 megacredits.
Riots and Civil Wars
When you tax colonists or natives below 40 happiness, they will begin to riot. Colonist rioting burns down factories and mines at a rate of 8 factories per turn and 10 mines per turn. Native rioting will destroy 3 factories and 5 mines per turn. If both colonists and natives are rioting, their structure destruction will be combined (11 factories and 15 mines destroyed per turn).
If a population's happiness drops to 30 happiness, you can no longer tax it. You must wait before happiness is above 30 before taxing again. If you try to tax, nothing will happen and the population's happiness will increase. Note: if you tax and the population's happiness ends at 30 or less, you will not gain any tax income for that turn. For this reason, you should never tax to a level below 31 happiness if you want to get tax income.
Once a population's happiness drops below 0, civil war will begin. When this happens, factories on the planet will be destroyed at double the rate of riots, and the planet's population will lose 30% of its clans plus another 100 clans per turn. Civil war will continue until happiness rises above 0 again.
Deliberately starting civil wars
To ruin an enemy planet, you can overtax the natives to deplete their happiness to prevent taxation, and so that they enter civil war. The most effective way to destroy a native population through civil war is to tax down to 31 happiness on one turn, and then tax as much as possible on the next turn. This will bring the native's happiness well below zero, which will lead to many turns of civil war. Since civil war kill both natives and colonists, the planet will become difficult for players to occupy, since many clans will be killed every turn. (The minimum number of clans you need on a planet to survive one turn of civil war is 144, which will leave you with 1 clan).
