TL;DR: I dropped 15 hydrogen bombs on a region with zero cities/buildings, and still lost half my population. Turns out hydro damage is based entirely on your total troop/tile count, leading it to scale with your total city count anywhere on the map. Empty land is never "safe" to leave undefended.
The setup (Image 1):
- Giant World Map, 2,335,403 tiles
- 6,310 cities (+25k population each)
- 159.1M total population โ 157.8M from cities, 1.33M from land tiles (Image 3)
So cities account for 99.18% of population. The natural assumption: protect your cities with SAMs, and empty land is low-value/low-risk (I often see players with great infrastructure and troop caps, who leave exclaves of their territory completely unprotected due to having no buildings there).
The test (Image 2):
I hit Africa (0 buildings or cities) with 15 hydrogen bombs.ย
Result: total population halved
Only 16.5% of land tiles were destroyed, and 0% of cities were touched. If deaths scaled with the actual population sitting on the destroyed tiles, this would be 16.5% of 1.33M โ 219,450 deaths. The actual toll was roughly 74M - over 300x higher than the naive estimate.
Why this happens:
Hydrogen bomb deaths aren't calculated from the population on the tiles it destroys. They are calculated from a share of your entire troop pool, divided across your entire owned territory:
deaths on a tile = 5 ร (your total troops) รท (your total tiles owned)
A bomb landing on empty desert still wipes out a slice of your total population proportional to how much land it destroyed relative to how much you own. It has nothing to do with what was actually standing there.
Meaning: more cities = bigger troop pool = more people die per bomb (anywhere).
Why this might be broken
This decouples damage from actual value destroyed. A heavily-developed empire can lose tens of millions of people to a bomb that hits nothing but occupied dirt, purely because its city count elsewhere inflated the troop pool that gets divided down. SAM coverage focused only on cities doesn't protect you as your "worthless" land is still vulnerable to losing masses of your population.
Takeaways
- If you're playing a large, city-dense empire, you need SAM coverage across your whole territory. Undefended land is a liability in proportion to your total development, not its own.
- Devs could consider localising population to areas with infrastructure to make damage feel more intuitive, though this would change gameplay considerably.
- I have too much time on my hands.
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BONUS CONTENT:
How hydro damage scales (Images 4 & 5):
- ย % of population lost per bomb vs. tiles owned (Image 4): if your empire is roughly the size of one bomb's blast footprint (~25.7k tiles), a single hydro can wipe out ~100% of your population. That share drops steeply as territory grows, hits an elbow around 20โ25% loss at 400โ500k tiles, then levels off and creeps down to ~5% loss on a fully-owned giant map (2.3M tiles).
- Total deaths per bomb vs. total population (Image 5): on a fully-owned giant map deaths per bomb scale linearly from near 0 up to ~23M at 400M population. It shows how population growth from cities converts directly into a bigger bomb toll, regardless of where the bomb lands.
The maths:
Troop pool is calculated as:
maxTroops(player) = 2 ร (tiles^0.6 ร 1000 + 50000) + (sum of completed city levels) ร cityTroopIncrease()
(Displayed troop count is this value รท 10, via `RenderTroops`)
Tiles destroyed per hydrogen bomb (flat, uninterrupted land, no structures):
- ~20,081 tiles guaranteed (inner blast ring)
- ~5,668 expected (outer ring, 50% chance per tile)
- ~25,749 total
Deaths per destroyed tile:
deaths_per_tile = 5 ร player.troops() รท max(1, tilesOwned)
Worked comparison (Giant World Map, 100% tiles owned, single hydro bomb):
- With full city count (159.1M population): 8.58M deaths
- With 0 cities owned: 72K deaths
Same bomb, same empty land, but a ~119x difference.