Impolite attacks
You might be thinking:
'Why can an attack be impolite? I help other players in defeating their legions - so I don't understand, why this can be impolite?!?'
Two reasons:
1. Let's imagine that your attack strength is 250.
Now if you fight a legion with 251 remaining health, it leaves exactly 1 remaining health point! However, this legion splinter must still be attacked with many villagers in order to have a 100% chance of victory. This is absolutely inefficient and means a huge waste of attack resources!
Remember that the main reason for attacking legions is for the resistance points (RP) earned. The number of RPs earned depends on the health removed from the legion by the attack. Removing N health points gives ? [note 1] resistance points. So removing 1 health point gives 1 RP for this attack, but the attacker still used several villagers which all lost the same amount of strength that they would lose removing maximum health points. The villagers would also lose 1 duration off their weapons, shields and helmets.
It doesn't break any rules, but it's unfair to the village owner or guild members who have to waste their resources on it!
As such, it is impolite to attack legions and leave them with low health. There is no official "limit" on how much health should remain. But since the combined strength of the villagers is well over 200, this would be a limit that can very well serve as a guide.
2. In some cases some players wish for a legion shall reach their village (eg. to gather the rewards for reaching the resistance levels again). Since there is still no "flag" implemented where a village can tell other players NOT to hit legions of this village there is a common practice:
The first attack on the village legion must be carried out by the village itself. Then the legion's health is no longer 2,300 and all players know that this legion can be attacked. If you see a legion with full health (2,300) that legion should NOT be attacked.