Core rules (differ from PvP): turn-based; player always attacks first and deals damage turn 1; if not killed in turn 1 the monster hits back and wounds troops; a tier/type disabled at 10% wounded; all disabled = loss. ZERO WOUNDS requires a first-turn kill: (1) raise ATTACK first (research/generals/equipment/skills/gear), (2) then troop COUNT, (3) use only CAVALRY, (4) use only a SINGLE TIER (mixing another tier just means turn 1 wasn't strong enough -- the turn-1 troops are always wounded, so extra tiers don't help reach 0). Wound caps: normally 10%; ground-troops-only fights and Monarch Talent Lv6 'Mortality' reduce it to 5%. Boss vs normal: for BOSSES the NUMBER of wounds drops in stair-steps as you add troops (there are plateaus where more troops don't help); for NORMAL MONSTERS the RATE of wounds drops in stair-steps. Turn order in mixed formations: highest tier first, alternating down; among types Ground attacks before Cavalry; RANGED only fight after ground+cavalry+siege are disabled (so ranged usually contribute nothing and can't reduce cav wounds); SIEGE take damage from turn 1 (bad). Two-turn economy: allowing one turn of wounds roughly halves the troops needed (Peryton: 85k for a 1-turn kill vs 50k for a 2-turn kill) but incurs wounds needing hospital/recovery -- weigh recovery cost vs troop-build cost. Measured per-turn wounds are ~constant per tier (t10 ~259, t11 ~208 in the test), which is why counts move in steps.
Original research source: Evony Guide Wiki
