Surprisingly little has been published by the collective Evony community regarding Battle Mechanics. Probably because each alliance wants to get as many advantages as possible, so there's no motivation to share information. If an alliance could develop their own working battle simulator, it would give them a huge advantage over the competition.
The best published work on Battle Mechanics is on DerrickD's YouTube Channel:
https://www.youtube.com/@DerrickDefies.
Essentially, he has figured out how 1-layer vs 1-layer battles work. He's now working on how 1-march vs 1-march battles work. Once that's figured out, the community may be able to start dissecting Rally vs Keep battles, and then maybe Rally vs Reinforced Keep battles, but I think those last two are still many months, if not years away.
The following is a summary of four (4) of DerrickD's videos.
Definitions
Troop Groups are multiples tiers of the same Troop Type (Ground, Ranged, Mounted & Siege) that start the battle moving and attacking together.
The correct troop range plus any applicable bonus is referred to as Actual Range (also differentiating from Published Range, which is often wrong).
The correct troop speed is referred to as Actual Speed (differentiating from Published Speed, which is often wrong).
Troop Groups can move and attack in the same turn if needed. So, Actual Range plus Actual Speed is referred to as Effective Range.
All-Troop In-Battle Functionality Rules
Troop Groups will move only if no enemy troops are within their Actual Range.
Once engaging enemy troops, Troop Groups will remain in the same location attacking the highest priority troop within their Actual Range until all of that enemy troop type is dead ORÂ a higher priority troop enters their Effective Range.
On the other hand, if no enemy troops are within the Actual Range after moving, then the Troop Group will not attack, and will wait there (only defending) until its next turn.
Ranged In-Battle Mechanics
Ranged Troops only have one (1) Troop Group, meaning all tiers move and attack together at the beginning of the battle. It may be possible for a Troop Group to separate later in the battle given specific scenarios.
Ranged Troop Priorities
Ranged Troops prioritize Enemy Troops in the following order (with Damage Bonuses/Penalties in Parentheses):
Theoretical Priority
Mounted (+20%)
Ranged (+0%)
Ground (-20%)
Siege [T-1 to T16] (+10%)
Actual Attack Order
However, because of speed, range and positioning dynamics on the battlefield, Ranged Troops are thought to attack Enemy Troops in the following order (with Damage Bonuses/Penalties in Parentheses):
Mounted (+20%) - Until all are dead, then move on to Ground
Ground (-20%) - Until all are dead, then move on to Ranged
Ranged (+0%) - Until all are dead, then move on to Siege
Siege [T-1 to T16] (+10%) - Until all are dead
Essentially, Ranged Troops stay back behind their own Mounted and Ground Troops while attacking the enemy Mounted and Ground Troops. Since they are out of the Effective Range of the enemy Mounted and Ground, the enemy Mounted and Ground will only advance once all their own Mounted and Ground Troops are dead.
Ranged (In-Battle) Movement Speed & Range Stats
Tier Published Speed Actual Speed
T1-T16 100 units/turn 100 units/turn
Tier Published Range Actual Range
T1-T16 500 units 500 units
Skill Book Published Range Increase Actual Range Increase
Level 1 +25 units +20 units
Level 2 +50 units +40 units
Level 3 +75 units +60 units
Level 4 +100 units +80 units
Maximum Effective Range (MER)
Maximum Effective Range is Speed + Range + Bonus(es).
Ranged MERÂ = 100 + 500 + 80 = 680 units.
Let me know if you have any questions.