Base Defense Facility Simulator (missiles/battleships/crackdowns, etc)

[Greep]

v2+++ Updated charts for vulcans and ninja landcruisers
v2++: Updated charts to reflect SAM nerf (350-100%->450-85%)
Removed SAM only chart as it's no longer a "special" building.
v2+:  Added crackdown odds to OP
v2:  now allows for mixed building types; fixed escape not closing app

Heya, so math sucks.  Why do math when a computer can do it for you?  (Simulator as attachment below)

Will let you know how effective your defense buildings are if you enter the # of buildings, their toHit and dam, and the offending object's HP.  Also works for vanilla xcom if you want to know how many missile silos you need for to stop X waves of battleships with Y certainty also.

Damage is assumed to be a spread of 50-150% and a miss is assumed to be 0 damage (both facts supported in a lot of places including the bootypedia)

This only says whether you are 100% successful in shooting down all the waves, doesn't calculate buildings lost on a successful missile strike (I actually don't even know the details of this anyways)

Also, I figure this would be a better place to talk about missiles if you felt like it than one of the generic threads.

Main takeaways for me:  To fully stop 3 waves of missiles, you need extreme overkill:

(Chances of flawless victory)
Overcharged Radars: 3 = 1.2%, 4 = 66%  5 = 99%
Flak Towers: 3 = 1.3%, 4 = 9.7%, 5 = 27.9%, (8 = 82%)
Flak Cannons: 3  = 44.7%, 4 = 70.8%, 5 = 86.4%
SAM Sites: 3 = 88%, 4 = 97%, 5 = 99.5%
Vulcan Battery: 3 = 53%, 4 = 82.7%, 5 = 94.6%

(costs to reach 60%:
Radars: ~3.5 million
Towers: Don't ask
Cannons: ~1 million
SAM sites: 700k)
Vulcan: ~2 million


Also the odds here:
https://www.ufopaedia.org/index.php/Base_Defence_Systems

Are 100 to 1 not 30 to 1 XD (24 buildings, 1 wave, 50 to hit, 500 damaged, 3000hp)


Full spoilers on crackdown deterring in piratez:

Spoiler:

Out of curiosity, I decided to delve into the ruleset for crackdown ships and generation, etc and decided to make a handy dandy chart.  Ship size is the same throughuot difficulties)

First the chances of given ships:

STR_ALIEN_HARVEST (? assuming no crackdown): 25%
STR_ALIEN_RETALIATION(uses "battleship" which actually seems to be a cruiser instead, it's 3500 HP whatever it is): 10%
STR_ALIEN_RETALIATION_L(assault transport, 1500): 15%
STR_ALIEN_RETALIATION_M(breaker, 900): 20%
STR_ALIEN_RETALIATION_S(boarding torpedo, 400): 15%
STR_ALIEN_RETALIATION_C(corvette, 2400): 15%

Harvest isn't counted in the chart below so , e.g. a cruiser is counted as a 13.3% spawn chance and so on.

The # of buildings needed to reach 80% defense are:

SAM Site: 9
Plasma Battery: 5
Gauss Battery: 6
Missile Silo:7
Laser Defense:7
Flak Cannon:13

The # of buildings needed to reach 98% defense are:

SAM Site: 12
Plasma Battery: 7
Gauss Battery: 9
Missile Silo:11
Laser Defense:12
Flak Cannon:18

The # of buildings needed to reach 99.97% defense are:

SAM Site: 14
Plasma Battery: 10
Gauss Battery: 15
Missile Silo:19
Laser Defense:15
Flak Cannon:26

The # of buildings needed to reach "lottery ticket" defense are:

Others: ineffective
SAM Site: 18
Plasma Battery: 15
Disruptor Shroud:22

The # of buildings needed to reach "Make a mathematician's head explode" (about 1:800^31)defense are:
Disruptor shroud: 31

The # of buildings needed to reach 100% defense are:
Disruptor shroud: 32

Note: SAMS have 5 beds, but no base defense turret if they get through

Note 3:  The above charts are only useful if playing ironman and is only for an unknown random encounter.  5 SAM sites will never stop a cruiser.  If you're reloading, the best defense buildings are missile silos since 3 can occasionally defeat a cruiser with 7% chance.

Foot patrol (early ninjas, ratmen, doom dudes)

Spoiler:

Flak cannons:
2: 76%
3: 90%
4: 96%
5: 98%
6: 99.3%

Vulcan:

2:80%
3:94%
4:98.5%

OC Radar:
4 = 100%

Disrupter Shroud:
3 = 100%

Higher tech buildings mostly just get close to 99% quickly

Ninja landcruiser individual odds:

Spoiler:

Chance for 60%
Vulcan:13
Flak cannon:12
Sam:7
Laser:7
Gauss:5

Chance for ~80%
Vulcan: 14
Flak cannon:14
Sam:8
Laser:8
Gauss:6

Chance for ~95%
Vulcan: 17
Flak cannon: 17
Sam:10
Laser:10
Gauss:8

Chance for 100%
Disrupter shroud:26

Ninja landcruiser All 3 destroyed:

Spoiler:

Chance for 98%:
Vulcan:19
Sam:11
Laser:12
Gauss:11
Plasma:8

Chance for ~99.9%
Others:ineffective
Sam:14
Plasma:10


Chance for ~99.9999%
Sam:16
Plasma:13

Chance for 100%
Disrupter shroud:26

[legionof1]

good tool. any chance it could be improved to account for mixed defense as the first base has?

[Greep]

If there's enough interest yeah, I just made a simple version because it was super quick.  For now you can use a quick heuristic of just assuming your low hit chance buildings generally make the difference when they hit.  So like.. 4 overcharged and an armored vault is probably something like... (100-66) = 34% * 0.3 = 10% get through so "about 90% odds" of all missiles getting shot down

[Greep]

Okay that also didn't take too long so I just did it xD v2 now allows for multiple building types

Turns out the correct answer to the previous example was 88.7% instead of 90.



EDIT:  Added a spoiler that shows full crackdown prevention odds with SAM sites.  Because mixed ships are used, SAM + armory towers > any of the early defense weapons (plasma batteries are pretty sweet)

The TL;DR version is that >=13 are needed to feel safe if you want to make a given base a fortress, but even as little as 5 will seriously cut down on crackdowns so they're useful in any base.  It seems like all races use all types of crackdown ships, so even putting 5 SAM sites helps considerably in stopping a Star God/merc base destruction.



Also just in case anyone is curious, yes on jack sparrow you can get 3x3 missiles strikes hitting a base for in a month for 9 buildings lost

[Greep]

Updated charts to reflect SAM site nerf.  In practice, simply adding an extra SAM or two gives around the same defensive capabilities, but there's now no "complete immunity" to early game missiles, at least not without spending 5 million in OC radars/disrupters.

[username]

My base defense strategy is just to immediately shit out 7 more bases that just have elevator shafts. Elevator shafts are immune to destruction so any missile that hits one is wasted.  With 7 fake bases, there's only a 1-in-8 shot that the missile is even aimed at the right target. 7 elevator shafts, nothing else, immediately gives 87.5% protection without any defenses.

[Greep]

I do something similar TBH.  Adding plantations and 40 dogs doesn't cost much, though.  And plantations/burrows/hi-res radars costs like nothing to replace.

[username]

I don't even bother with radars. At that point in the game, I have no ability to intercept anything anyway, so I don't need to see it, it just interrupts gameflow. It isn't really until you get Nightmares that you can actually intercept anything at all that isn't immediately in your face or will actively pursue you, and even then, most things aren't interceptable until Sabres, so there's little point in even trying, as most enemies clock in around 5K+ speed, so even Nightmares can't effectively close with them unless they're already very near you and nothing else should even bother trying.

[Greep]

Updated Charts for vulcans, foot patrols, landcruisers.

Edit: Updated landcruiser flawless victory, fixed an error in the faction crackdown charts (accidentally flipped the SAM and laser accuracy I think, or maybe it was changed in an update)

-Added some additional silly settings to crackdown odds.