dxcalc accurately calculates the outcome of a battle for the online browser game Evony.
The basic idea is to fill in the attack and defense armies and other known information and hit the submit button. The submit button changes it's name but it's near the middle, underneath the Technology table.
It is very helpful to know the exact value of all parameters for both attacker and defender. Sometimes you can get away with estimating some values, but it is useful to test high and low estimates to get a feel for how important an unknown parameter might be.
new_bonus = heroes_base_attack * 0.25
The value to use in dxcalc is attack + new_bonus.
The number of traps that trigger each round is randomly chosen by the Evony server at the beginning of each battle, so we don't know exactly what it will be for a particular battle. The rate option allows you to try some different trap rates. Setting this value in the calculator is like pretending that the server will actually use that value for the real battle.
The main reason to have it as an option is so you can try different values to see if it affects the results of a battle. In many cases it will not change the results much. But in some cases, especially when attacking layers are thin and there are a lot of traps, a different value could have a large impact on the results. If you do see a large effect when changing the trap rate you should realize that the result of the battle is uncertain and relying on one outcome or another is a risk.
Note that the actual trap rate is typically between 4.0 and 9.0.
Like the trap rate, the kill power of these fortifications vary from battle to battle. The "pow" pull down allows you to specify this power. If there are a lot of these fortifications it is worth checking higher and lower values of "pow" to see how it might affect the outcome. For example, the variability in NPC 10 hits is mostly due to random differences in trap power.