In Earth: Empires, a retaliation, or retal for short, is a type of military action made by a country in response for an earlier act of aggression against that country. For example, country A sends a standard strike against country B. This is called a landgrab. Country B then sends a standard strike back against country A, in an attempt to get the lost land back. This is called a retaliation. In alliance servers, most alliances have policies for how they retal against certain types and certain amounts of attacks against them.
In alliance-based servers, the concept of retaliations is an interesting affair. How retaliations are handed out varies from alliance to alliance, and even from player to player. Some alliances may have countries specifically built to handle retaliations, should one of their alliance mates suffer an attack that he/she cannot retaliate him/herself--a basic concept of what is known as 'tag protection'. Some alliances may vary how many retaliations are sent back to an attacker based on the number of attacks sent, or the amount of resources lost. Following is a list of established policies that alliances usually follow.
Some alliances consider the 1:1 as standard retaliation against other alliances--one retaliatory attack for every incoming attack. This policy was once the de facto standard back on Earth:2025's Alliance server, but it was phased out due to the growing number of topfeeds occurring against alliances. This policy has made a small comeback in recent years, due to the realization of a stagnant game.
Most alliances used this policy on alliances that are not pacted to them. The concept of this policy is slightly more complicated than the 1:1 policy. For each subsequent attack on an alliance, the amount of added retaliations increases.
Most alliances accept this general method of 1:1, escalating: 1:1 2:3 3:6 4:10. If someone attacks an alliance using this policy one time, the alliance retaliates once (1:1). If someone attacks the same alliance twice, the alliance retaliates three times (2:3), or, 2+1=3. If attacked three times, the alliance will retaliate 6 times (3:6), or, 3+2+1=6. And so on. If more than four attacks are made against an alliance, that alliance may either choose to farm the offending country, cripple the country to keep it from being able to attack them again, or kill it.
Under this policy, alliances strive to take as much land back from an attacker as that attacker took from their member. Multiple retaliations may be used to accomplish this. This policy was adopted by most alliances after the rise of top-feeding began to make gameplay unfair in the eyes of the alliances. However, it soon became a defining reason for the old Earth:2025 game becoming stagnant, as there was no point of using landgrabs as a method of interaction between players or alliances if there wouldn't be any gains made from them.
Retal on Retal
A Retal on Retal, or ROR, is when a country knowingly or unwittingly retals a hit that was itself a retal. This leads to typically escalated punitive measures, as encouragement to accept further retals. Often FA's of alliances will have to come to an agreement as to how to proceed, as there is often confusion on the part of the countries involved.
When someone attacks an individual country playing by itself, such as a country not in a clan or alliance in an alliance-based server (or, untagged), the retaliations made by that untagged country may take the form of anything, such as special attacks (missile attacks, bombing runs, etc) or harmful spy operations against the attacking country. These lone countries generally don't consider themselves as subject to the rules established by others, so they feel that they are free to act in whatever methods they wish to retaliate. These methods of retaliation are generally not accepted by established alliances, and can result in the untagged country being farmed even more heavily or even killed.