Mission frequency?

[Gifty]

I'm noticing in 1.0 that there seems to be a dramatic increase in terror missions (2-3 a month), while standard UFOs seem much rarer; I tried several new campaigns at various difficulties and terror missions started popping up immediately, while it would sometimes take two weeks just to spot a UFO. Is it just me? Was the original game like this and I'm just remembering incorrectly?

1.0 is fantastic, regardless.

[Emre]

Same here, i always blame the RNG though.

[skyhawk]

In addition to the Battlescape AI, I think they haven't been able to fully duplicate Geoscape alien behavior.

In the little bit I've played, on Beginner and Experienced difficulty, I've seen a Base Attack with psionic-capable Sectoids in January, and a terror mission with psionic-capable Sectoids and Cyberdiscs in early February (That one kicked my ass, of course).

I don't remember the original game ramping up the enemies quite that brutally fast.

Sometimes there is UFO activity in areas not covered by your base(es). Check the graphs from time to time. If there's activity outside your coverage, consider sending the Skyranger or an Interceptor to maintain patrols around those areas.

The plus side for all of this, of course, is that it feels like you're fighting a war against an unpredictable and aggressive enemy, unlike EU(2012), where it feels like you're just playing a computer game.

[Hobbes]

In the little bit I've played, on Beginner and Experienced difficulty, I've seen a Base Attack with psionic-capable Sectoids in January, and a terror mission with psionic-capable Sectoids and Cyberdiscs in early February (That one kicked my ass, of course).

I don't remember the original game ramping up the enemies quite that brutally fast.

Both situations can happen in the OG. Remember that your radar doesn't have a 100% chance of detecting all UFOs so it's possible that it misses the Retaliation scout that is generated after you shoot down a UFO near your base.

[osunightfall]

I'm noticing in 1.0 that there seems to be a dramatic increase in terror missions (2-3 a month), while standard UFOs seem much rarer; I tried several new campaigns at various difficulties and terror missions started popping up immediately, while it would sometimes take two weeks just to spot a UFO. Is it just me? Was the original game like this and I'm just remembering incorrectly?

1.0 is fantastic, regardless.

I don't know... I feel like I've had a lot of different experiences in the first month. I know that sometimes I've gone the entire month and not spotted a single UFO, only to get the terror mission at the end of the month. I don't know that I've seen three terror missions in a month but it might be possible. I've definitely seen two. And I know playing on veteran in the classic game I've definitely had a sectoid base invasion in month 1.

[darkestaxe]

Terror sites are very rare early in the first month and can't really happen before the twentieth in vanilla. Also you can't have 3 in the first month in vanilla. It's different in OXC but I haven't been playing the more recent builds.

A terror mission has to be completed for the terrorsite to happen and that takes at least a few weeks in vanilla. The aliens only start with one terror mission in vanilla and I've never seen them start another until they complete the first one. I have seen that a few times in OXC so it's a difference, though I don't know if it's intentional.

If you go through the entire first month without detecting a single UFO in vanilla then your radar glitched. The game will send UFOs to fly around your base until you detect them at first and the odds of going 10-14 hours without detecting an in range UFO are extremely low. Since the vanilla game will send multiple UFOs on missions around your base in the first month the odds of not detecting any are negligible.

Suppose there's only 4 UFOs and each is only in range of your base for 10 hours total and you have 1 small radar.  The chances of not detecting it in vanilla X-COM are 95% each hour. 0.95^240 = 00.00045% or 45/10,000,000.

[Gifty]

It's really hard to accurately gauge this stuff just on gut reactions, but having weathered several more months, the terror missions seem to have leveled out. I had to bump it down to a lower difficulty, though, the UFO distribution seems sparse enough that you can't catch enough of them on Superhuman and it's much easier to bleed points and lose without having many battles.

I've found my groove, though, things are working out. Hope this thread didn't read too much like a complaint, I'm really digging the changes now that I've found my way again.

[Warboy1982]

In addition to the Battlescape AI, I think they haven't been able to fully duplicate Geoscape alien behavior.

for the record, the geoscape AI and timing is 1:1 with the original.

the battlescape AI is about as close to the original as we can come, with some slight enhancements. Julian really did a great job with this, which is not surprising considering it's at LEAST third generation.

Terror sites are very rare early in the first month and can't really happen before the twentieth in vanilla. Also you can't have 3 in the first month in vanilla. It's different in OXC but I haven't been playing the more recent builds.

it's not different in OXC.

I've never seen them start another until they complete the first one. I have seen that a few times in OXC so it's a difference, though I don't know if it's intentional.

it's intentional, a new terror mission begins with a randomized delay at the beginning of each month. two terror missions can be running concurrently without issue, just not in the same region, and the timings will be offset to the extent that they'll take place at least 20 days apart unless xcom starts shooting them down (in which case all bets are off).

The game will send UFOs to fly around your base until you detect them at first

sort of.
the first alien mission will always be sectoids doing alien research in the same region as your starting base.

[darkestaxe]

I didn't explain what I was saying very well.

I've seen OXC running multiple terror missions in the first month and had multiple terrorsites at the same time in the middle of January (with older builds). Once I was sending a skyranger to one of two terror sites in january and detected another terrorship along the way. That was a long time ago though, it may have been back before you guys imported the geoscape mission data, which I remember reading about in the development section. I re-read OP and it doesn't sound like he's describing that sort of thing anyway.

it's intentional, a new terror mission begins with a randomized delay at the beginning of each month. two terror missions can be running concurrently without issue, just not in the same region, and the timings will be offset to the extent that they'll take place at least 20 days apart unless xcom starts shooting them down (in which case all bets are off).

That accurately describes what I remember from vanilla and what seems to be happening in my current OXC game. He shouldn't be getting 2-3 terrorsites a month in january - march right?

[Warboy1982]

teeeechnically it could be possible, if you shoot down enough of january's terror ships to delay it until march, and february's doesn't show up until after the 28th. i mean, the odds of all the RNG calculations falling in line like that are miniscule at best, but i wouldn't discount it completely.

[Gray Carlyle]

I play on SH too, and found the geoscape behaeviour of the AI strange. I´m at end of April, and so far I encountered not more than 25 UFOs, most of them being sectoids and I got my  third terror site cleared up, the last one against floaters.

I played the OG last year extensive on SH and there were subjective much more alien activity on the geoscape and more races at this date than it is here.

But anyway, you guys did a fantastic job here.

[Empiro]

I play on SH too, and found the geoscape behaeviour of the AI strange. I´m at end of April, and so far I encountered not more than 25 UFOs, most of them being sectoids and I got my  third terror site cleared up, the last one against floaters.

I played the OG last year extensive on SH and there were subjective much more alien activity on the geoscape and more races at this date than it is here.

But anyway, you guys did a fantastic job here.

Yeah, this issue seems to be often reported (I reported this a while back too). It's really hard to prove one way or the other though.

I think the best way to help gather more evidence would be start several games in both OpenXcom and the original around different spots in the world. Then, cheat in a Hyperwave Decoder. Wait 2 months, and count the average number of UFO detections in each game.

[Hobbes]

Yeah, this issue seems to be often reported (I reported this a while back too). It's really hard to prove one way or the other though.

I think the best way to help gather more evidence would be start several games in both OpenXcom and the original around different spots in the world. Then, cheat in a Hyperwave Decoder. Wait 2 months, and count the average number of UFO detections in each game.

I'm checking the UFOPaedia page on the MISSIONS.DAT file and while the info there is incomplete, there are significant differences between the what's listed and the content on Alien Missions on the XCom1.rul file.

For instance, Abduction missions appear listed on MISSIONS.DAT consisting of 6 UFOs, while on the ruleset there are only 5 UFOs being generated. Another major difference is that the time on the UFOPaedia's Ruleset Reference page is defined as seconds, which seems wrong, considering when comparing those values with the ones that appear on MISSION.DAT, and should be minutes instead.

Another major difference seems that the time between UFOs is actually random and can vary between 50 and 150% of the listed time.

[Hobbes]

OK, I've decided to look at the code concerning mission generation and found out that the UFOPaedia needs an update. There's a couple of interesting things in the code.

First, from the comments in the code the value in the timer on the Alien Missions waves is either:

Code: [Select]

The actual value used is spawnTimer/4 or 3*spawnTimer/4
The first UFO that appears on Alien Research has a timer of 9000, so it can appear at 1,5 days (2250 min) or 8,3 days. As I posted above, the info on the UFOPaedia states that UFOs can appear between 50% and 150% of the spawnTimer this value, but the formula listed on OXC's code actually sets the possible dates as either 25% or 75%, so if all of the info is correct then there are really more UFO missions on OpenXCom.

EDIT: After reading Warboy1982's comment about the RNG I looked better and more digging into the code found this:

Code: [Select]

_spawnCountdown = (spawnTimer/2 + RNG::generate(0, spawnTimer)) * 30
So, mission time can vary randomly but only between 50% and 100%, whereas on the UFOPaedia the range of values is listed between 50-150%, which still explains that people are seeing more UFOs and aliens missions on OXC.

[Warboy1982]

uh... check your math.
_spawnCountdown = (spawnTimer/2 + RNG::generate(0, spawnTimer))
half plus anywhere up to a whole.
that describes 50-150%
as for the comment in the code, ignore that, it's a comment. i never updated it when i fixed the algorithm.
it doesn't matter if the units are in minutes or in seconds or in aeons, as long as the numbers equate to the same thing.
I've gone over this a thousand times. don't take ufopaedia as a 100% credible source: it's not one.
but seriously, why does nobody believe me? am i THAT untrustworthy? it's really frustrating.
whatever, dig all you want, i don't care any more.