Forts or walls

[Qon]

Can't find the topic I was looking for, but this is a (slightly outdated) topic about lans mines :
viewtopic.php?f=5&t=57500
Note : Now, landmines benefit from explosives damage upgrade .

Nice!
Also, that's Infinite explosive damage upgrades!
Though research for instakilling behemoth spitters with mines is quite expensive. But you can place them close enough that they trigger 2. Even biters are instagibbed if you go high enough. And since they are stunned even a single line of lasers easily take them out.

[Koub]

Indeed. Or you can fill the range difference between a flamethrower turret and a spitter with mines, and let the fire puddles tear down the incoming waves.
Well tbh, this is pure theory for me, I almost never get to that point on my maps, but it should work.

[Qon]

Indeed. Or you can fill the range difference between a flamethrower turret and a spitter with mines, and let the fire puddles tear down the incoming waves.
Well tbh, this is pure theory for me, I almost never get to that point on my maps, but it should work.

I did some testing. Wrote about it in another thread:

I just learned that mines stun the enemies they affect. And it's also AoE and can be placed at long ranges (roboport construction area). That could really prevent all damage as long as you don't send bots to replace the mines while under attack. A big part of the swarm would be dead before they even reach turret range and when they do they will be stunned in turret range instead. While stunned they can't charge forward and they can't spit but you are free to BBQ them to the perfect temperature, just season to taste and you have a 5-star meal. Really gives your flame turrets the time they need to act on targets at long range and to hit the first wave. Flames + Mines seems like a beast combo if you have my laser wall as backup. Maybe detect enemies at long range by measuring oil used and don't insert mines into logistics chests until the level stabilises?

Edit:
I tested it. There's no way any behemoth swarm can get through a mine+flame defence. Had a single row of laser in case they came close to my walls. That was way overkill. Walls was also overkill. Laser almost never shoots at all and the behemoths can't get through half the mine layers. They basically stop at the first layer. I removed several layers of mines to keep the furthest layers + spitter range within flamer range and it was still overkill.

However, if you don't stop the bots from replacing mines you are going to have a really bad time.
Your fire damages your bots and your mines. While attacks are going on you will lose thousands of bots and mines if you place them during the attack and quite a while after. The bots will fly into the fire and burn to death. When they survive they place a mine in fire or acid spit the mine instantly dies. Since flamethrowers are free to shoot at immobile targets the ground flames last a long time after the fight too. Also even if they do manage to place a mine a spitter will attack mines that are not armed so it will be killed as it is placed by a spitter that you can't reach with your turrets. This will trigger a new mine placement which keeps the spitter immobile outside of your turret range because you keep feeding it new un-armed mines to spit at. At least the flame AoE is about the size of a mine so if your mines are spaced out enough to not destroy each other then the flames burn the mines that have already exploded since those are the ones with natives on them. So they don't destroy armed mines.

Mines + flames is probably overkill regardless of swarm size and how few mines and flame turrets you downsize to. But the weakness is that you can't rebuild the mines while attacked and quite a while after or you will lose all your mines and bots in the first attack. So if you get attacks very often at the same spot you will need the lasers to help the flamers when the mines are out. But with artillery, you mostly get bursts of attacks with a long time in between since they only attack when they migrate into your automatic range or you upgrade your range or manually fire.

Edit2: Apparently mines can't damage eachother according to a thread I just read. But if you place them too close to each other your flames will kill the surrounding mines that haven't yet exploded.
But this means that you are free to place mines as close as you want if you use lasers instead of flame turrets. And then you can definity stunlock all of them outside spitting range and replacing them can be done immediately when your lasers stop firing. Which someone has posted a neat detector for! :3

Note : Now, landmines benefit from explosives damage upgrade .

That's infinite landmine damage research!

But I did some more testing and mines alone are actually enough if you fill the entire roboport construction area. Just don't replace them during an attack and you are good. Simplest is to just not have them in a logistics chests except every 10 minutes or so. A simple timer circuit can put them in a steel chests so con bots can't grab them and then move them to a provider for a few seconds and then back again to the steel chest. Turrets are not actually necessary. And by not having turrets the spitters will not have anything to spit at. A whole behemoth swarm can only get through like 2-3 layers of mines so even if you have a single artillery turret so that they all beeline into the same spot you can take continuous attacks by really aggroed behemoths for minutes at the same spot before they even get close enough to get shot my laser turrets. If you have several turrets then that means you spread out their attacking spots. If you don't have a lot of expansion then you barely ever need to replace the mines once you cleared out your artillery range.

Flame turrets are extremely strong with mines. But then you have to spread out your mines because with 1 mine/tile the flame AoE will destroy surrounding mines. And flames last a long while when pooled at the same spot on immobile stunned targets so you can't replace the mines for quite a while after being attacked. It's strong enough that you could probably fairly easily deal with behemoths with 10 times the health, but also annoying that you can't just chance on no attack going on at the time when you release the mine replacements. And mines alone are already strong enough. If you use lasers then that isn't as good combo power wise, but anything with mines is already overkill in terms of defensive power so it's not like you endanger yourself if you use lasers instead of flamers
But lasers don't linger after a fight so you can place mines immediately when the fight stops. And you can pretty much eliminate drain from lasers (follow the quote arrow link) and you don't need many turrets since they just do some irregular cleanup or never ever fire depending on how many layers of mines you have.

So mines are god mode if you don't rebuild them during an attack or while the ground is burning.

[vanatteveldt]

Land mines sound cool

Are there good ways to detect an attack? I guess you could use oil use from flamethrower (tank level goes down), ammo use by gun turret (belt moves), laser turret accumulator draw. Do people use anything like this, or is "once every 10 minutes" fine, and replace the bots if they happen to trigger during an attack?

[Qon]

Are there good ways to detect an attack? I guess you could use oil use from flamethrower (tank level goes down), ammo use by gun turret (belt moves), laser turret accumulator draw. Do people use anything like this, or is "once every 10 minutes" fine, and replace the bots if they happen to trigger during an attack?

Yes, there's good ways. The thread I was quoting myself from was my thread where I do just that Perfect 0~drain Laser: Blueprintable and Chunky!
You just have to read the signals on of the power switches gets. You can't rely on pure solar(+accumulators) during the night though since accumulators can't charge other accumulators. It is fail-safe, it "assumes" an attack is going on in that case so the turrets are ready to fire. But a night lasts like a few minutes only and you don't have to replace mines very often so it isn't a big deal. For some locations, you can just carpet the ground with mines and just never replace them before you expand past them and pick them up again to move them further out.

But you can only detect enemies like that within the range of your turret. Even if flame+mines has longer range and is an extremely powerful combo, lasers don't have a lasting ground flame that kills your bots and mines long after the fight. And lasers + mines is still extremely powerful and easier to measure and know when it's safe to deploy mines again. You should probably reduce the number of lasers to a single line deep if you combo with mines to reduce cost. More isn't needed since the mines themselves is actually enough. The primary use of lasers is detecting when the attack is over.

I would place mines like up to 22~ tiles away from the lasers since they have a range of 24. And with lasers, you can place the mines as tight as possible. Filling the space all the way up to the lasers with mines is overkill, you just extend the time it takes to do the initial build. Since you can detect when an attack ends and replace the mines immediately a few lines of mines is enough.

Both ways are viable and have different complexities and advantages.
Having lasers to detect when an attack happens means you can't really effectively use mines past the range of lasers though. And just having mines alone and taking a chance every 10 minutes (or so, needs a bit more testing on what is reasonable) and blindly replace and take the losses is probably good enough. But lasers + mines, on the other hand, can basically guarantee that the natives will never even attack once and you can skip repair packs because mines are not attacked (after being armed) and stun the enemies. So both biters and spitters (behemoth range 16) can't ever get in range to attack.

[vanatteveldt]

Sounds fun, I'll have a try when I get game time again

Couldn't you even place some 'tripwire' lasers a bit further out, and rely on mines + flames for real defense? Somehow I dislike lasers, they feel too cheaty...

[Qon]

Yes. But skip the flamers and put the mines further out instead. You want the mines to protect your sensing turret from being attacked. The mines just have to be in range of the turrets so you know when the attack stop. Without the flame turrets you can pack the mines more densely and can replace the exploded mines when the attack ends instead of when the flames die, which is undetectable and needs some guesswork.

Basically, take my 0 drain design but skip all the laser turrets except the one that's used to detect enemies. Also, get rid of the walls. Mines are walls that kill the natives. But walls can get damaged by mines while mines are immune to mine explosions.

For the natives to get through a many layered mine field you probably need creative mod and a max evo and max density enemy death world and suddenly upgrade your artillery range many steps instantly so you can aggro everything with several kilotiles range and have them all come at you at once. And only have like 4 artillery turrets so they all take the same path where mines have already exploded. That's what I did to see how long it would take q:
If I had more artillery turrets they probably wouldn't have been able to break through ever even without replacements before I cleared them all out because they wouldn't make "tunnels" of corpses through the mine field

[Qon]

[0.17.37]:

Bugfixes

• Fixed acid splashes were blocking placement of buildings. (70317)

Makes mines better! Now bots won't hover over acid splashes until spitters kill them. They just place the mine and leave instantly so your bots don't get attacked. Uninterrupted mine replacement still mean that a spitter can have a fresh new mine to spit on forever if your bots are quick enough to replace any mine before they move. But burst replacement every 10 minutes or so doesn't really suffer any major losses any more if it happens during an attack. You just lose some of the mines since they can be attacked during the first seconds after placement. But it's such a small loss and bots are pretty much safe. So now my recommended strategy is to just no let bots replace mines all the time with a simple circuit.

If you limit the provider chest to a single stack then you don't even have to pull them back out now, it won't hurt that much if a few of them are leftover. Pulling them back out is slightly better, but I'm not sure it is worth it if you find the circuit that would do that tricky. So just activate a stack inserter for 20 seconds or so every 10 minutes and limit provider chest to 1 stack and that's all you need to have an effective and cheap mine defence that only costs you some cheap mines and never needs repairs.

[adam_bise]

Lol I never would have guessed you can place mines via bots. Cool!