When engaging in PvP combat in Atlas, it's important to know your strengths, as well as that of your opponents. Troop losses can swing from a 1:10 ratio in your favor, or a 10:1 ratio in the opponent's favor--don't let this happen to you!
When engaging in Primarch vs. Primarch combat, the most important things to note are:
(1) Primarch's Attack and Defense Ratings:
When you Attack, your Primarch's ATK rating is pitted against the opponent's DEF rating.
When you Defend, your Primarch's DEF rating is pitted against the opponent's ATK rating.
If we went equal-level Sieger vs. Sieger on defense, we'd get decimated because our Sieger here only has 53 DEF to the opponent's 249 ATK – almost a 1:5 difference!
(2) Fort Bonus is just as important as the Primarch's attack and defense ratings because they're almost the same thing! When a battle takes place on a Castle with a Fort, the "Home team" gets the Fort bonus added to the Primarch's ATK or DEF rating.
For example, if I'm at my Home Castle, and my level 5 Fort grants +100 Fort bonus, any attack or defense my Primarch is involved in will gain that bonus to its stats:
- I am the attacker: ATK + 100 / DEF
- I am the defender: ATK / DEF + 100
You can see how the tables can quickly turn if the enemy's Fort is very high level!
*Siegers function in the opposite manner, REDUCING the Fort bonus by a flat amount per Sieger. This debuff stacks.
(3) Sheer Army size plays a factor too, starting around 15% at the point where one Army is twice the size, gradually getting worse for the smaller army to around 50% when the opposing force is four times as large.
(4) Total Base Destruction, or number of Flames is another major factor. The more favorable the battle's outcome is i.e. closer to 100% destruction, the better the outcome for that player.
* Player Level has no numerical effect on combat, but does make the player stronger as a defender due to base layout and tower levels.