Exchange Attack Wave
Most commonly referred to as an “ex” or “x” wave on most servers but some servers will call this a tradefire wave or “tf”. This is typically an attack that is used more so early on in a server where defending with archers is quite common. The entire concept of this wave is get archers in a position where the archers can exchange fire, thus the name.
Evony Battle Mechanics
The idea is simple, basically you are exploiting the defenders mechanics by causing the archers to stop for one round to kill the incoming cavalry when facing someone in a ranged defense. This creates equal movement and causes the attackers and defenders archers to encounter each other at the same time to then exchange / tradefire. If you do not kill all melee units in front of the defenders archers it can cause this wave to fail or do very poorly as it will need to engage other units rather then archers as seen below.
Exchange attack waves are much more effective if it has a strong hero. The better the hero the better the result. Also if the defender has a low count of archers and can possibly pass into another exchange round you can do more damage. The first example below features a weak hero, however the defender has a low archer count and able to force the exchange into an extra round thus killing more. Here are two examples.
Weak Hero, low defending archer count
Stronger Hero, lots of defending archers
Dynamics of the attack wave
This attack wave will consist of mostly archers since these are what will do damage to the defender. You will layer this with a low amount of cav do maximize how many archers you can send. This wave can be performed in range and compact. However this wave is best for range since if they are in compact and have archer towers they may be difficult and costly to kill. I have shown you multiple reports on this wave for a reason because when you read the section about delayering you may discover something you did not know regarding abatis.
Defending against the Exchange / Tradefire attack
First thing I’d like to point out that is very effective against this wave is mech defense because it simply out ranges the incoming archers. Though this can be a great defense you must make certain you have a large amount of mechs and a strong hero. This attack can slowly chip away at small amounts of your defending mechs until you have a collapse. If you see that you are losing any mechs at all, you have a serious problem and need more mechs or stronger hero asap. If an exchange waves kills your mechs this is what will happen.
Layer up (1 pike)
If you are simply defending with archers your best defense is to layer up with “1″ of all melee units. Your first unit you must layer with must always be 1 single pike. The pike alone will stop this attack. After your pike is up then get other layering in place.
Switch to Compact
Switch to compact if you have the troops and the towers to kill. This can especially be the case if you have an instant archer tower hero. Your towers can take quite a bit of damage and be especially difficult to take down if they are sending poor heroes. When archer towers are down you will want to switch back into range to avoid archer exchanges. When switching to compact make certain you do not get jaq/viof’d. Make sure you always have melee layers to prevent this.
Compass Level 9
By not researching to compass 10 this affects the battle mechanics and your archers march speed. This is a good counter to this wave particularly early game. This will make you immune to these waves altogether. Keep in mind that all your troops will march just a bit slower.
Battle Mechanics - Delayering
In short this means going massive sums of abatis to delayer/kill the attackers cavalary. What this does is remove their cavalry before round progression even starts. So they are essentially sending a pure archer attack wave. As long as you keep abatis count high they will be killing nothing and have no clue why. Keep them guessing when you do this or they will start sending larger amounts of cavalry and this method will be ineffective. Read more about delayering here.
This is a great attack wave early in the game and go do massive damage if you are catching a defender offline. However if you are online you should have more then enough tools to stop this attack completely. As your server advances this will likely become used less and less as people transition to more mechs. Good luck attacking and defending.