When to Use Nukes — Costs, Blast Radius, SAM Coverage

An atom bomb costs 750,000 and a hydrogen bomb 5,000,000. A city costs 125,000, so one atom bomb is six cities and one hydrogen bomb is forty.

Which gives you the answer most of the time: late, and only against someone you cannot out-grow. Gold spent on nukes early comes straight back as falling behind.

Prices

Item	Cost
Missile Silo (prerequisite)	1,000,000
Atom Bomb	750,000
Hydrogen Bomb	5,000,000
MIRV	25,000,000, rising 15,000,000 per launch
SAM Launcher	1,500,000 (3,000,000 from the second)

MIRV cost scales with how many you have already launched: 25,000,000, then 40,000,000, then 55,000,000.

Blast radius

Type	Inner (total kill)	Outer (damage)
Atom Bomb	12	30
Hydrogen Bomb	80	100
MIRV warhead	12	18

The hydrogen bomb’s inner radius of 80 is far larger than the atom bomb’s outer radius of 30. It costs 6.7× more and destroys considerably more than 6.7× the area.

Troop casualties are computed from density (5 × troops ÷ tiles owned). A target with troops packed into a small area is worth far more per warhead. Against a sprawling empire, one atom bomb hurts much less than you would expect.

Silos and range

Nukes launch from the nearest silo and land where you clicked. Default targeting range is 150 tiles.

• Silo reload is 9 seconds
• Construction takes 10 seconds; upgrades shorten reload
• Silos are buildings, so they transfer with territory. Never build on the border

A silo site has to satisfy two conditions at once:

1. Targets within 150 tiles
2. Outside enemy SAM range

SAM — what it stops and what it does not

SAM range grows with level:

range = 150 − 480 ÷ (level + 5)

Level	Range
1	70
2	81.4
3	90.0
5	102.0

It approaches 150 asymptotically and never exceeds it. Level 5 is the point where it finally covers a hydrogen bomb’s 100-tile blast.

The MIRV misconception

“SAMs cannot stop MIRVs” is the usual shorthand. More precisely:

SAM targets are atom bombs, hydrogen bombs, and MIRV warheads. Warheads are on the list. What is not on the list is the MIRV carrier before it splits.

The real reason MIRVs get through:

• A MIRV splits into multiple warheads that arrive together
• SAM reload is 9 seconds
• While it engages one, the rest land

So it is not “cannot intercept” — it is “cannot keep up with the salvo.” Several SAMs will stop part of it, but blanketing your territory in SAMs to counter a 25,000,000 attack is rarely the better trade.

Building one after the launch is too late

SAM construction takes 30 seconds. If you start building when you see the missile, you will not finish. Build it when a neighbor first acquires a silo.

So when?

Situation	Call
Early to mid, land still available	Don’t. Cities dominate
Target has troops packed tight	Peak atom bomb value
Sprawling large empire	Border pressure beats nukes
Chokepoint held by defense posts	Careful — fallout adds further defense multipliers
Closing out a won game	Hydrogen bomb on troop concentrations
Target has only a level-1 SAM	Range is 70. Fire from outside it

Gold priority is almost always: three cities → ports and factories → defense posts → (much later) silos and nukes. Reasoning in How Many Cities Should You Build?.

Two side effects

• Fallout persists and adds a defense multiplier to those tiles. Nuking land you intend to take works against you
• Using a nuke can break alliances. Be careful firing near allied territory

More

• Building cost calculator — silo and SAM totals
• All Six Buildings — silo and SAM placement
• How Many Cities Should You Build? — the opportunity cost