**SCENARIO 1: Basic calculation**
Defense is calculated exactly in dominion. If you send only one point more modified (**mod**) offense than your targets modified defense, you will break him. Any less and you will fail.

Raw defense is simply the total defense value of all his units. For example a Human:

- Draftees: 1,000 (1 point of defense)
- Archers: 1,000 (3 points of defense)
- Knights: 2,000 (6 points of defense)
- Cavalry: 500 (3 points of defense)

This gives 1,000 + (1,000 x 3) + (2,000 x 6) + (500 x 3) = 17,500 RAW defense
Next you must consider mods, which are summed together before being applied to raw defense. If your target has:

- Ares Call On (10% bonus)
- Guard Towers: 10.00% (20% bonus)
- Walls improvement: 5.00%

This gives your target 0.10 + 0.20 + 0.05 = 0.35 or 35% mods.
Thus your targets modified defense is 17,500 x 1.35 = 23,625

Your own offense is calculated in the same way. If you are a Goblin attacking with 3,000 Wolf Riders, that gives you 3,000 x 6 = 18,000 RAW offense.

If your mods are:

- Killing Rage On (10% bonus)
- Gryphon Nests: 10.00% (20% bonus)
- Forges improvement: 10.00%

Then your total mods are 0.40 and your modified offense is 18,000 x 1.40 = 25,200, more than enough to break the target. In fact, you can break him sending 2,813 Wolf Riders. It's good to send a little extra just to be safe, but don't overdo it if your attacking elite also has a defensive value. Sending unnecessarily large amounts of troops to attack is wasteful when you could have left many of them home to help defend.

**SCENARIO 2: Using barracks spies**

Lets look at a situation where you are invading an attacker whose troops are out on invasion.

- Draftees: 1,000 (1 point of defense)
- Archers: 1,000 (3 points of defense)
- Knights: 2,000 (6 points of defense)
- Cavalry: 4,000 (3 points of defense)

You can see by the unit layout that this dominion has a lot of cavalry, the Human offensive elite. He is clearly an attacker, not an explorer like the last target, and most attackers (except those whose offensive elite has no defense value, such as Lycanthrope and Dark Elf) are very difficult to break while their attacking force is at home. To check if his army is out attacking, you must do a barracks spy.
Suppose a barracks spy reveals that 3,300 cavalry are out attacking and only 1,000 are home defending. Barracks spies are only 85% accurate, so to compensate for this you need to consider the worst case scenario, or the most cavalry he can possibly have at home. This can be determined by dividing the number home in the barracks spy by 0.85 (NOT multiplying by 1.15 as many mistakenly believe). 1,000/0.85 = 1,177 cavalry home maximum (always round up).

This target's raw defense is 1,000 + (1,000 x 3) + (2,000 x 6) + (1,177 x 3) = 19,531 RAW defense. You can then apply mods to get his final defense.

For more information on barracks spies, see **scenario 5**.

There are two ways to determine the maximum amount of cavalry he has at home. You can either divide the number home by 0.85 (number home method), OR you can multiply the number away by 0.85 and then subtract from the total number of cavalry he has (number away method). The number away method obviously requires a clear sight to determine how many total units the target has, so is not as useful against magic races whose clear sights can be difficult to obtain eg Sylvan and attacking Icekin. But on a regular target where you have a clear sight, you can try both methods on the barracks spy and use whichever one gives you the lowest number of offensive units home. Which one this is depends solely on which way the barracks spy inaccuracy goes, which is randomly determined. For our barracks spy here the number home method gives 1,177 max cavalry home while the number away method gives 4,000 - (3,300 x 0.85) = 1,195. Thus the number home method gives a better number in this example. It doesn't make a big difference here at all, but when you are attacking, for example, a Troll, whose army is comprised entirely of Smashers, it is imperative that you use both methods and see which gives you a lower defense, as the difference between them can be quite large.

**SCENARIO 3: Using temples**

Go back to **scenario 1**, and this time assume you have 10% temples. Temples reduce enemy mods by 1.75 x Temple%. Thus 10% temples would reduce 17.5% mods.

The target in scenario 1 with Ares Call on, 10% guard towers and 5% walls would now have the following mods:

0.10 + 0.20 + 0.05 - 0.175 = 0.175 or 17.5% mods

Thus the target would now have modified defense of 17,500 x 1.175 = 20,563 (again, always round up for your target)

**SCENARIO 4: Units with variable defense values**

Calculating the defense of targets whose unit values are variable is not much more difficult. Assume the following Wood Elf:

- Draftees: 0
- Longbowmen: 1,000 (4 points of defense)
- Mystics: 2,000 (variable based on forests)
- Druids: 500 (variable based on forests)

You will need a Land Spy to calculate his defense. Assume this land spy shows 82.50% forests. Wood Elf elites have a base defensive value which increases by 1 defense point for every 20% forest. Therefore the values for this target are:

- Mystic: 4 + (0.825 / 0.20) = 8.125
- Druid: 1 + (0.825 / 0.20) = 5.125

Raw defense is (1,000 x 4) + (2,000 x 8.125) + (500 x 5.125) = 22,813. You can then apply mods.

**SCENARIO 5: Attacking “half blind”**

Attacking half blind refers to attacking without gathering full information on your target. Say for example you wish to attack a Dark Elf. Since their defensive elite also has magical abilities, DEs have a very high wizard-per-acre ratio and can be extremely difficult to clear sight for a non-magic race. You can get around this by taking several barracks spies.

In this situation you are attacking a Dark Elf explorer with gargoyles and adepts, but no draftees. Assume the target has 15.16% wizard guilds, giving his adepts a defensive value of 4 + (0.1516 / 0.10) = 5.516 each.

You take 3 barracks spies which show the following numbers for his units:

- Barracks spy 1: 1,541 gargoyles, 3,862 adepts
- Barracks spy 2: 1,021 gargoyles, 4,451 adepts
- Barracks spy 3: 1,443 gargoyles, 3,601 adepts

Know that on any given barracks spy, each unit has a different inaccuracy applied to it. Thus if a barracks spy underestimates his adepts, it does not necessarily underestimate his gargoyles as well. As a result, look for the lowest values for each individual unit, even if they come from different barracks spies. In this example we use 1,021 gargoyles (from the 2nd barracks spy) and 3,601 adepts (from the 3rd barracks spy).
Thus to get his maximum unit count, we divide these numbers by 0.85. This dominion has a maximum of:

- 1,021 / 0.85 = 1,202 gargoyles
- 3,601 / 0.85 = 4,237 adepts

Maximum raw defense is (1,202 x 3) + (4,237 x 5.516) = 26,978. If the targets only mods are Ares Call (we assume it is on, if we cannot get a clear sight we definitely can’t get a revelation) then maximum final defense is 29,676.
If you send 29,677 offense, you are absolutely guaranteed to break this target. If you are feeling lucky then you can send a little less than this and hope for the best (you are after all using his maximum defense values and not precise numbers). The less than this you send, the bigger the risk that you fail your attack. And obviously the more barracks spies you take, the more accurate your estimates will be for his maximum defense.

Attacking in the absence of surveys and castle spies (eg on Halflings and Lizardfolk) can be a lot more problematic. You can either:

- Use old survey/castle information from your realm's op center, if available
- Assume “high” guard towers and walls (this is subjective… say 15% GT and 12% walls)

Method 1 can work pretty well, though to be safe you should assume his GT and walls have increased slightly. Method 2 is not as effective, as it carries both a risk of failing your attack or oversending by a huge amount. You would do best to post on your council for any Halflings or Lizardfolk in your realm to help you get the info you need (do not ask people outside your realm, this is considered cheating).

**SCENARIO 6: Land Defense**

You should note that all targets have a minimum defense of 1.5 * Land, and that mods are applied to this defense. This is called Land Defense. Assume that right OOP you are attacking an inactive target on 300 acres with the following military:

- Draftees: 302
- Archers: 10
- Knights: 10
- Cavalry: 10

Ares Call is off since the target is inactive, but he has 5.00% Guard Towers giving him a total of 10% defensive mods.
The target's raw defense from military is 422. However his land defense is 1.5 * 300 = 450. Since raw dp cannot be lower than land defense, this targets raw dp is 450. We then apply 10% mods to get a final defense of 495.

Land defense is only really an issue right OOP or at very small sizes, but nonetheless you should be aware of it.

Lastly, there is an automated calculator available to premium account holders that will perform most of the above calculations for you if you copy/paste the information gathered on your targets. Just remember, though, that getting better at this game involves knowing how the calculations work and being able to check them yourself as well. You should familiarize yourself with the above.