X-COM OpenXcom Thread

[Average Manatee]

https://www.ufopaedia.org/index.php/MISSIONS.DAT#Retaliation

According to this page which is directly looking at the mission data for aliens, retaliation missions only target a zone, which goes by these semi-continental regions:

https://www.ufopaedia.org/index.php/File:WorldMap_RegionalZones_Ufo.png

So if you have two bases in the same zone they should both be perfectly findable for aliens. I'm not sure if it's just a case of "if the missions complete, they find a base" or if the alien ships are actually searching in a radius around their flight paths. The "Aggressive Retaliation" option for OpenXcom would seem to suggest the latter.

I checked the OpenXcom savefiles (which are plaintext) and they show the same thing about UFOs targetting zones:

  - type: STR_ALIEN_RETALIATION
    region: STR_CENTRAL_ASIA
    race: STR_SECTOID
    nextWave: 2
    nextUfoCounter: 1
    spawnCountdown: 10080
    liveUfos: 0
    uniqueID: 17
    missionSiteZone: -1

EDIT: OpenXcom sources confirm that Alien UFOs have a sight radius of 80 units.

/**
 * Only UFOs within detection range of the base have a chance to detect it.
 * @param ufo Pointer to the UFO attempting detection.
 * @return If the base is detected by @a ufo.
 */
bool DetectXCOMBase::operator()(const Ufo *ufo) const
{
   if (ufo->getTrajectoryPoint() <= 1) return false;
   if (ufo->getTrajectory().getZone(ufo->getTrajectoryPoint()) == 5) return false;
   if ((ufo->getMission()->getRules().getObjective() != OBJECTIVE_RETALIATION && !Options::aggressiveRetaliation) ||   // only UFOs on retaliation missions actively scan for bases
       ufo->getTrajectory().getID() == UfoTrajectory::RETALIATION_ASSAULT_RUN ||                                        // UFOs attacking a base don't detect!
       ufo->isCrashed() ||                                                                                               // Crashed UFOs don't detect!
       _base.getDistance(ufo) >= Nautical(ufo->getRules()->getSightRange()))                                           // UFOs have a detection range of 80 XCOM units. - we use a great circle fomrula and nautical miles.
   {
       return false;
   }
   return RNG::percent(_base.getDetectionChance());
}

I wonder if UFOs can still detect bases outside of the target zone when they are entering and exiting the atmosphere on their usual cross-planet high speed trajectories. In that case they could certainly just randomly be within 80 units of a base.

Also interestingly, larger bases are easier to detect:

/**
 * Calculate the detection chance of this base.
 * Big bases without mindshields are easier to detect.
 * @param difficulty The savegame difficulty.
 * @return The detection chance.
 */
size_t Base::getDetectionChance() const
{
   size_t mindShields = std::count_if (_facilities.begin(), _facilities.end(), isMindShield());
   size_t completedFacilities = 0;
   for (std::vector<BaseFacility*>::const_iterator i = _facilities.begin(); i != _facilities.end(); ++i)
   {
       if ((*i)->getBuildTime() == 0)
       {
           completedFacilities += (*i)->getRules()->getSize() * (*i)->getRules()->getSize();
       }
   }
   return ((completedFacilities / 6 + 15) / (mindShields + 1));
}

Though, a full 36 tiles taken up would only increase the detection chance from 15% to 21%. Also this detection runs every 10 minutes.

 

[ArchAngel]

And how much is 80 units?

 

[Average Manatee]

Good question. It says it's using nautical miles, but then https://www.ufopaedia.org/index.php/UFO_Detection says that the in-game ufopedia is off by a factor of 5, and other wiki pages give conflicting info. From what I can gather from looking at the data through XcomEx's stats page the radar range of a Skyranger is 672 nautical miles so 80 nm would be close to 1/8th that.

However I did also find this:

    if (Options::aggressiveRetaliation)
   {
       // Detect as many bases as possible.
       for (std::vector<Base*>::iterator iBase = _game->getSavedGame()->getBases()->begin(); iBase != _game->getSavedGame()->getBases()->end(); ++iBase)
       {
           // Find a UFO that detected this base, if any.
           std::vector<Ufo*>::const_iterator uu = std::find_if (_game->getSavedGame()->getUfos()->begin(), _game->getSavedGame()->getUfos()->end(), DetectXCOMBase(**iBase));
           if (uu != _game->getSavedGame()->getUfos()->end())
           {
               // Base found
               (*iBase)->setRetaliationTarget(true);
           }
       }
   }
   else
   {
       // Only remember last base in each region.
       std::map<const Region *, Base *> discovered;
       for (std::vector<Base*>::iterator iBase = _game->getSavedGame()->getBases()->begin(); iBase != _game->getSavedGame()->getBases()->end(); ++iBase)
       {
           // Find a UFO that detected this base, if any.
           std::vector<Ufo*>::const_iterator uu = std::find_if (_game->getSavedGame()->getUfos()->begin(), _game->getSavedGame()->getUfos()->end(), DetectXCOMBase(**iBase));
           if (uu != _game->getSavedGame()->getUfos()->end())
           {
               discovered[_game->getSavedGame()->locateRegion(**iBase)] = *iBase;
           }
       }
       // Now mark the bases as discovered.
       std::for_each(discovered.begin(), discovered.end(), SetRetaliationTarget());
   }

It looks like if aggressive retaliation is off that they can only detect the last base (presumably the most recent) in each region. So I guess in theory if you build an empty base on the edge of the zone your main base is in, the aliens will never be able to find the main base without finding the empty base first (which you just rebuild instantly)?

EDIT: Actually I think that it means that if aliens discover multiple bases in a region that they only remember and launch one retaliation against the last base they saw. But if they only find one base then they'll launch retaliation against that base regardless. Aggressive retaliation would mean they could discover both and launch two retaliations simultaneously (or perhaps more for more bases in a region). Someone could test this by building all 8 xcom bases ontop of each other.

 

[octavius]

I started a new game of TFTD on Genius, since I forgot to adjust the mod list and settings before starting my previous game (stupidly bringing along a tank to the first ship rescue has of course nothing to do with it).

I've alway been too timid to attack grounded ship, but this time I decided to live dangerously. It's funny how the Small ships are more of a pain than Medium ships in these situations. With Small ships there's this very cramped first room, and too much valuable equipment in the adjoining rooms to go all in with explosives.
But with the Medium ships the first room is large and empty of instruments, and you get a pretty good line of sight into it.
In my current game three of these ships landed right next to each other within in the Bermuda Triangle, so I guess there is a base there.

 

[Average Manatee]

Yeah that small TFTD ship is basically a design from hell. There's absolutely nowhere safe to stand in that thing. An alien can walk 3/4ths of the way across the ship and still shoot you point blank. You really want the motion scanner so you know where the targets are and can rush them.

Ground assaults are great, they don't trigger retaliation like shot down UFOs and the UFO power sources are what explode in the crash, losing you 250k cash and essential elerium along with whatever else they hit. Always take them unless it's a night mission and you'd rather shoot them down to make it a day mission.

 

[index.php]

https://www.moddb.com/mods/x-piratez/downloads/x-piratez-m5-the-five-captains

X-Piratez v.M5 24-Mar-2022 The Five Captains

- OXCE Upgrade to 7.5.3 7-Feb-2022
- Fix: Nun outfit crash
- Fix: Lost Souls recovery
- Fix: X-Vampiress revival no longer available to Green Codex only
- Fix: Killing own cameras no longer gives you "betrayer" while "saving" hideout's defensive turrets - "cavalier".
- New Missions: Zombie Baiting, Food Pirates, Humanist Tank Test, Witch Quests (x6)
- New Enemy: Vampire Lord
- New Enemy Vessels: Black Helicopter, Marauding Army, Rogue Courier
- New Enemy Missions: Bandit Revenge, Ratmen Revenge, Vampire Incursion, Rogue Courier Run
- New Facilities: Revolution HQ (sprite based on Vangrimar's work), Dungeon, Hotel
- New Armors: Maid /PEA (inspired by Interdictor, Bloax & Mikkoi); Furs/PEA & Winter Queen & Skullgirl (based on Interdictor's submod); Sicarius (PEA only; gfx by Brain); Durasuit (PEA & SS); Cleanser (SS only; gfx by Jim)
- New Weapons: Smart Cannon (gfx by XOps), UAC Laser Rifle (gfx by Brain), Ol' Marksrifle
- New Ammo: EMP Rocket
- New Gfx: Bandit Armored Car sprite and wreck (by Bulletdesigner), Armored Church Beastmaster paperdoll (by Brain), Pillbox sprite
- New Gfx: +8 Gal Avatars
- New recruitable special characters (10) from events
- New Urban map by CosmicAfro
- New Maps (5) for UAC Vaults, more loot
- New Music, Music added to many events
- New Events: beyond count
- Fixed insane refire rates of enemy craft on Jack Sparrow, damage per shot raised to compensate for lower diff.
- Flak Tower is now Resilient, storage increased to 50, missile hit priority increased
- Craft Weapon strings expanded to cover multipurpose slots as well
- Charger Laser much more expensive to buy to account for the cost of parts, buffed to compensate
- Replaced placeholder Magical Girl sprite with proper one
- Sound improvements/expansions (most sounds taken from Piratez HQ Soundpack by RSSWizard)
- Limits put on MBT's cannon (mechanics suggested by berriebun)
- Much more Bombs can be carried, but refire on DV and MS slots slowed down a bit
- Peasant Gladiatrix armor buff (better stats + Purple shield)
- Autofire range on most assault rifles +1
- Flamethrowers 33% more killy
- Mumbleball has more potent morale effect but now ignores only 82% if armor (thx to EricdaMidget for field tests)
- Golden Codex: OnlyRunts feature added
- Peasant Revolution: added Scavenging, Propaganda, Reinforcements, Revolution HQ
- Dr. X Arc: added Black Knight Armor (gfx by Brain)
- Some pixels rearranged on some maps for Hobbes to finally sod off (by Solar)
- Minor graphics fixes
- Other fixes, upgrades & stuff

 

[octavius]

Is it common in TFTD that there's no sub sightings the first one and a half months, only Terror sites, on Superhuman?
Or have I just had bad luck twice in a row?

 

[Alienman]

Probably just bad luck.

 

[octavius]

Started a new game and called the base Defect Sonar. Not we're suddenly spotting sub.

 

[Average Manatee]

Where did you place the base that is detecting nothing?

The aliens should prioritize your starting base area for month one. Issue is that TFTD areas can be huge (pacific ocean). If your base is in Pacific they might be running missions against anything from Australia to USA I think. I'm not sure but maybe they'd even target USA and then go for the Atlantic coast, just because USA counts as in Pacific.

If you want to figure out where UFOs are going you can look at the alien score in each region and correlate it with the wiki maps to see where they are scoring points.

Spoiler

 

[Endemic]

Is it common in TFTD that there's no sub sightings the first one and a half months, only Terror sites, on Superhuman?

Or have I just had bad luck twice in a row?

Actively searching them out by patrolling with your Barracudas and Triton is mandatory. Your base sonar is only about 20% effective by itself - combined with the fact that oceans are more than double the area you needed to cover in the original, it's going to be much harder to find alien craft.

As Manatee said, checking graphs will help.

 

[octavius]

Where did you place the base that is detecting nothing?

North Atlantic, covering as much ocean as possible.

Actively searching them out by patrolling with your Barracudas and Triton is mandatory.

Hmm...Barrucadas don't have much fuel, and the penalty for the Triton not reaching a Terror site in time can lose you the game.

 

[Average Manatee]

Where did you place the base that is detecting nothing?

North Atlantic, covering as much ocean as possible.

Might retry with a smaller starting zone like mediterranean or caribbean. I usually go North Atlantic though and it's pretty rare to find nothing at all.

Actively searching them out by patrolling with your Barracudas and Triton is mandatory.

Hmm...Barrucadas don't have much fuel, and the penalty for the Triton not reaching a Terror site in time can lose you the game.

Patrolling in place takes vastly less fuel than movement so if you use them like that as stationary radars it can last pretty long. For terror sites you can always abuse the bug where the terror site can't expire while a craft is heading towards it (even if that craft is a Barracuda). Unfortunately there's no great solution aside from rushing one or more radar bases.

 

[octavius]

Well, on my third try in North Atlantic I got three sightings the first month. One got away, one was shot down and the third was assaulted when grounded. Then I got a Terror mission on January 31st, but thankfully at daytime. Lost six 'nauts and all civilians, so got a negative score, but fortunately the good scores from the two sub missions more than weighed up for it.

Spoiler

 

[Endemic]

Last time I played TFTD Superhuman i had 4 USOs + the terror mission in month 1, RNG is quite fickle. You can also get early base attacks which is fun

 

[Cael]

The massive maps in T FTD becomes so tedious after a while. I prefer the original.

 

[Average Manatee]

Started a game and I think this might be a good way to go about the early game. Sacrifice the traditional upgrade from small to large radar in the main base (Mediterranean doesn't really need it anyway) and get the atlantic big radar up quickly. Managed to just barely squeeze in a lab, alien containment, and 14 aquanauts/26 scientists thanks to selling some excess craft equipment. Will need two living quarters to get started within the first two weeks which is a bit tight but should be doable.

Spoiler

Also, something of a bonus, but the mediterranean is so small that your crafts can cover 100% of it which is nice because they have 100% detect rate rather than 10% of your small radar. So if you're afraid that your radar is just missing them you can get around that.

The massive maps in T FTD becomes so tedious after a while. I prefer the original.

I do agree but its a good change once in a while. Probably worth playing 1 TFTD game for every 3-4 X-Com games.

 

[Cael]

Why didn't you put the access lift where your general stores is in your first base? Like in your second base except in the middle rather than on one side. That would give you an additional layer of space to play with.

 

[Average Manatee]

Don't know what you mean by "additional layer of space" exactly. I don't need to build more facilities at once so I'm not slowed down at all.

Enemies can spawn in the access lift and the design of the room blocks line of sight through it. The way I have it designed means completely unobstructed line of fire from the bottom of the map to the hangers, meaning I can just spam rockets across the map into the enemy spawn during invasions and my guys are all crouched in smoke at the maximum distance away.

Access lift:

Normal base facilities:

 

[Cael]

Like this:

HHHHHH
HHHHHH
.....L
The rest
..of the
..base


You can still spam rockets through the lift if you so desire. You just need to blow up the doors first.

 

[Average Manatee]

Multiple good reasons:

1. I'm ~90% certain those doors can only be destroyed by blaster bombs IIRC. They 100% certainly can't be destroyed by gas cannon HE (recall that TFTD torpedoes can't be fired unless in water).
2. Aliens can spawn in the L which is closer to the bottom of your base.

Spoiler

Here's the sight distance of an alien, with a lift in the way you'd lose 10 spaces of distance to put between you and their spawn. Chryssalids can run a bit further and still hit you.

3. You have more room for facilities.

HHHHHH
HHHHHH
__L___
BBBBBB
BBBBBB
BBBBBB

Only gives you 18 slots for base facilities

HHHHHH
HHHHHH
L_BBBB
_BBBBB
BBBBBB
BBBBBB

Gives you 21 base facility slots.

In particular I like to do

HHHHHH
HHHHHH
L_SSSS
_QQQQQ
RBBBBB
RBBBBB

S = storage. Since you can never be sure who ends up where in base defense, you want to have some motion scanners not assigned to soldiers. Whoever spawns in storage can go up the stairs, get a scanner, and you'll easily spot everything coming towards you and most of the stuff in the hangers.
Q = Living Quarters. According to wiki this is where soldiers are prioritized spawning though I'm not sure about this tbh, they seem to spawn in labs and workshops just the same.
R = Radar. Radar also has both a bad room pathway that blocks LoS and also is a bit vulnerable to destruction. So I keep it off to the side. It can be in either of the R spots and I swap between them when building a large radar to replace the small or hyperwave decoder to replace the large.

The only real problem with having the lift on the edge of the base like this is that if you want to build a whole base from scratch it's pretty slow because you can only build a few things at a time. Either you commit to building two hangers sequentially first or you branch down a radar and more buildings from the south of the lift and then if you want to make it defensible you'll have to demolish and rebuild the radar later.

 

[Cael]

Multiple good reasons:

1. I'm ~90% certain those doors can only be destroyed by blaster bombs IIRC. They 100% certainly can't be destroyed by gas cannon HE (recall that TFTD torpedoes can't be fired unless in water).
2. Aliens can spawn in the L which is closer to the bottom of your base.

Spoiler

Here's the sight distance of an alien, with a lift in the way you'd lose 10 spaces of distance to put between you and their spawn. Chryssalids can run a bit further and still hit you.

3. You have more room for facilities.

HHHHHH
HHHHHH
__L___
BBBBBB
BBBBBB
BBBBBB

Only gives you 18 slots for base facilities

HHHHHH
HHHHHH
L_BBBB
_BBBBB
BBBBBB
BBBBBB

Gives you 21 base facility slots.

In particular I like to do

HHHHHH
HHHHHH
L_SSSS
_QQQQQ
RBBBBB
RBBBBB

S = storage. Since you can never be sure who ends up where in base defense, you want to have some motion scanners not assigned to soldiers. Whoever spawns in storage can go up the stairs, get a scanner, and you'll easily spot everything coming towards you and most of the stuff in the hangers.
Q = Living Quarters. According to wiki this is where soldiers are prioritized spawning though I'm not sure about this tbh, they seem to spawn in labs and workshops just the same.
R = Radar. Radar also has both a bad room pathway that blocks LoS and also is a bit vulnerable to destruction. So I keep it off to the side. It can be in either of the R spots and I swap between them when building a large radar to replace the small or hyperwave decoder to replace the large.

The only real problem with having the lift on the edge of the base like this is that if you want to build a whole base from scratch it's pretty slow because you can only build a few things at a time. Either you commit to building two hangers sequentially first or you branch down a radar and more buildings from the south of the lift and then if you want to make it defensible you'll have to demolish and rebuild the radar later.

The enemy spawns in the hangar as well. Your row of storage or whatever gives them multiple corridors to wander into your base...

Also, just about anything, including laser rifle hits, will blow up the lift doors.

 

[Average Manatee]

The enemy spawns in the hangar as well. Your row of storage or whatever gives them multiple corridors to wander into your base...

That's fine, they don't have the range to see and shoot me and I can shoot them. The more damage you do to the enemy through applying high explosives to their spawn point on turn 1-3, the more likely they'll suffer morale failure and panic. Remember we have motion scanners parked on the upper floor to detect the exact position of any alien coming near, they can't flank us.

Also, just about anything, including laser rifle hits, will blow up the lift doors.

Completely false. I just tested and rockets don't. Maybe plasma would but it'd take several turns of shooting to go through a lift which is a total waste of time and gives the enemy time and space to be more dangerous.

 

[octavius]

Just made 4 millions from a mission in TFTD. The economy really gets out of whack once you conserve your explosives...
Now I can buy that fully equipped base instead of just a sonar station.

 

[Cael]

The enemy spawns in the hangar as well. Your row of storage or whatever gives them multiple corridors to wander into your base...

That's fine, they don't have the range to see and shoot me and I can shoot them. The more damage you do to the enemy through applying high explosives to their spawn point on turn 1-3, the more likely they'll suffer morale failure and panic. Remember we have motion scanners parked on the upper floor to detect the exact position of any alien coming near, they can't flank us.

Also, just about anything, including laser rifle hits, will blow up the lift doors.

Completely false. I just tested and rockets don't. Maybe plasma would but it'd take several turns of shooting to go through a lift which is a total waste of time and gives the enemy time and space to be more dangerous.

I play with laser rifles exclusively once I get them. My standard unit loadout is laser rifle, stun rod, medikit and electro flare.

They blow through any human doors easily.

This is with original XCom, though.