Use OpenXCom Extended+. It improves everything and allows to add mods!

[PMBELL]

OpenXCom Extended+[openxcom.org] is an open source version that uses the original game files so you do need to buy the original game .
It really improves the interface and makes the game easily moddable (there are even total conversions for it!). For instance, I made the Heavy Cannon shoot arcing shots, 'cause it's a grenade launcher, right? Unfortunately that made grenades obsolete, so I scratched it.
A few links you may like:

• List of differences between OpenXcom and vanilla: OpenXcom[www.ufopaedia.org] (bear in mind that most can be toggled off and behave like vanilla).
  
• Best reference site: UFOPaedia[www.ufopaedia.org]
  
• Active forum: OpenXcom Forum[openxcom.org]
  
• Good site: Strategy Core[www.strategycore.co.uk]
  
• Mod site: http://www.openxcom.com (may not be working as it should)
  
• Mod site: Open Xcom Mods[openxcommods.weebly.com]
  
• Total Conversion mod: XPiratez[openxcom.org]

[DeepFried]

what *exactly* does it change. Almost every large mod i've used on any game in the past makes the game worse by just changing too much, stuff that didn't need changing. The odd bug fix, fine, the odd convenience fix, fine, but touch a hair on the head of the actual game machanics and thats a no.

[PMBELL]

See the differences in: https://www.ufopaedia.org/index.php/Differences_to_X-COM_(OpenXcom)

You can play *almost* exactly like vanilla. You can play it even in linux (an android version is on the way). You have a list of settings to change from vanilla. Most are conveniece fixes like showing your current funds and radar coverage in the Geoscape, soldier sorting, autoselling manufactured products (LC), showing which are 2 handed weapons, showing stats in the inventory screen, 80-item limit (you can keep it!).
There are some minor differences with crafts: they use the shortest route in the globe (a greatcircle) heading towards the current position of UFOs (vanilla used compass bearing), stay in the air even when below 50% fuel if they still have fuel to return to base and you can unequip all weapons on them. Also they rearm before refuelling (as opposed to vanilla). And of course the AI that can't be 100% replicated for certain.
Some modifications that I like are for instance to hide that an enemy has panicked if you don't see it in battlescape, etc.

[Tetsuri]

you actually want to touch some hairs on the actual game. Once you've gained some experience into how the game is played you will appreciate options liek autosell and autosetup, which are things you have to redundantly repeat on your own otherwise that don't change how the game is played at all except reducing the amount of unnecessary and annoying busywork.

most of the hardcoded features in OPENXCOM improve the experience and doesn't change the gameplay, the rest is all customizable:
https://www.ufopaedia.org/index.php/Differences_to_X-COM_(OpenXcom)

it fixes a lot of issues that made the game less desireable to play, for example issues with frames on certain maps, with smoke present, etc...

the only major change is that they can't completely replicate enemy logic, but you won't even notice that difference unless you're a super experienced vet at this game that can predict how they'll move every turn, and from wat I've seen on the forums, even a lot of long time players still don't even understand this game.

I'd urge you to look at the list of known bugs, which have mostly been fixed in OPENXCOM, and then make your consideration off of that.
https://www.ufopaedia.org/index.php/Known_Bugs

If you own TftD, I'd much more strongly recommend getting OPENXCOM for that, as it's guaranteed to fix the research bug, which breaks the game.

well, it doesn't really matter if you want to play without OPENXCOM. All I can say is, if you delay, and get it later, I told you so, and if you decide not to get it, you miss out and I don't suffer any.

[Ivlichnov]

I played the unmodded version of XCom first, but Open X Com includes a lot of bug fixes, and brings improvements which make the original game play better. The mod also makes better use of modern higher resolution monitors.

OpenXcom 1.0 Feature Trailer
https://www.youtube.com/watch?v=GL2x-Sz9Oa8

[PMBELL]

Configuring the display to look good is a bit tricky. The best results I got are:
1280x720 resolution, 1.5x original Geoscape and Battlescape scale, Fullscreen, Sabr Xcomified render engine, Letterboxed display.

[Aaron]

no dont use openxcom extended you dont need it the only time you need xcom extended plus for some mods that dont go well with open exteneded i use openxcom and thats all you need for nearly alll mods

[Aaron]

PMBELL の投稿を引用：

OpenXCom Extended+[openxcom.org] is an open source version that uses the original game files so you do need to buy the original game .
It really improves the interface and makes the game easily moddable (there are even total conversions for it!). For instance, I made the Heavy Cannon shoot arcing shots, 'cause it's a grenade launcher, right? Unfortunately that made grenades obsolete, so I scratched it.
A few links you may like:

• List of differences between OpenXcom and vanilla: OpenXcom[www.ufopaedia.org] (bear in mind that most can be toggled off and behave like vanilla).
  
• Best reference site: UFOPaedia[www.ufopaedia.org]
  
• Active forum: OpenXcom Forum[openxcom.org]
  
• Good site: Strategy Core[www.strategycore.co.uk]
  
• Mod site: http://www.openxcom.com (may not be working as it should)
  
• Mod site: Open Xcom Mods[openxcommods.weebly.com]
  
• Total Conversion mod: XPiratez[openxcom.org]

honestly pal just use OPENXCOM you dont need openxcom plus or any other stuff, just openxcom but when i want to play XCOM FILES I USE OPEN XCOM EXTENDED

[Aaron]

for normal game modes i use open xcom and yes it is better than vanilla all bugs fixed now most anyway i also disable psi if aliens cant see me SO ONLY THEY AND ME CAN USE PSI IF WE SEE EACH OTHER I USED TO HATE XCOM FOR THAT ALIENS USING PSI ANYWHERE ON THE MAP PANICKING EVERYONE so now its line of sight only i also use advanced base starter so my hangers are at the top and i get bit more stuff sometimes i play without depends on mood if im up t o the challenge even on normal difficulty this game is hard lol BUT ITS BETTER THAN THE NEW XCOM 1 AND 2 PUT TOGETHER IM SICK OF DEVS SIMPLIFYING GAMES XCOM WAS UNIQUE

[Aaron]

FINALLY FORGET TERROR FROM THE DEEP THAT GAME IS BAD , whoever thought of doing underwater stuff needs firing they ruined xcom by making terror from the deep could of been so much better xcom apoc is better than terror from the deep i absolutly love xcom apoc i use a mod that balances the game fixes a lot of stuff in xcom apocaslspe

[DeViLhoOD]

Azza35 の投稿を引用：

FINALLY FORGET TERROR FROM THE DEEP THAT GAME IS BAD , whoever thought of doing underwater stuff needs firing they ruined xcom by making terror from the deep could of been so much better xcom apoc is better than terror from the deep i absolutly love xcom apoc i use a mod that balances the game fixes a lot of stuff in xcom apocaslspe

TFTD is not bad if you like underwater stuff, like me. And it's especially good with OpenXcom and The world of (terrifying) silence mod.

I've always been fascinated with the water since I was a kid, and I played TFTD loads on the PSX. Fantastic game imo.

Also, OpenXcom Extended has numerous improvements such as better pathfinding and some QoL improvements inspired by XcomUtil.