A city boss is the one fight in Shadowrealm that the whole realm shares. It attacks a city, every player present can hit it, and it either dies to the collective effort or it sacks the city. It is also the clearest example of a fight nobody can win alone.
Bosses come in four difficulties, and the gap between them is not cosmetic: an Ancient has more than twice the health of a Lesser and roughly five times the attack, alongside a far better reward.
A boss stays up for 24 hours. If it is not killed in that time it force-expires and the city is sacked. The window is sized around an assumed turnout of about 20 participants. The higher tiers are genuinely not beatable by a handful of players on natural energy regeneration, and they are not meant to be.
A sacked city carries a gold penalty on its residents and stays sacked for 24 hours, so ignoring a boss has a real cost even for players who never intended to fight it.
Each attack costs 10% of your maximum energy rather than a flat amount, so the cost scales with your character instead of penalising small pools. Every landed hit also pays a flat 50 XP regardless of outcome, which makes participation worthwhile even when your damage contribution is modest.
The boss hits back. Your own Defense and Dodge apply to its retaliation, so a durable character can sustain far more attacks per session than a glass-cannon build, which matters more here than in any other fight in the game.
Every boss carries two pools, one of gold and one of shadowgems, and both are split the same way. 50% of each pool is shared out EVENLY among every fighter who qualifies, and the rest is shared out by damage dealt. You need at least 3 landed hits to qualify for either pool.
No single fighter can take more than 25% of a pool, so it takes at least 4 fighters to claim a boss outright, and anything a capped fighter would have taken above the ceiling goes to the rest of the raid instead.
Gear and material drops work differently: they are rolled per fighter, with a higher damage share improving your odds. Bosses use their own dedicated drop tables rather than borrowing an action's, so what a boss drops is tuned to the boss rather than inherited from somewhere else.
The practical read: turn up early and keep hitting. Qualifying at all already earns a real, predictable share of both pools, and damage on top of that is what decides whether you take an average slice or the largest one.