Community Discussion - Air Combat
By Chris, September 6, 2019 in Xenonauts-2 General Discussion
Chris 497
Beloved Leader
The air combat section of Xenonauts 2 has gone through a number of iterations over the past few years, and with the project approaching Early Access we've taken the decision to switch to (an upgraded version of) the realtime air combat mechanics from the first game rather than pursuing the alternative turn-based model I've been experimenting with. I'll explain the reasons for this change below, but let's start by discussing the realtime mechanics and the planned improvements.
Realtime Mechanics:
We're already working on implementing the realtime air combat mechanics from the first Xenonauts and we're hoping to have them in the next major release (V8). This will also include various supporting strategic systems such as the ability to manufacture advanced aircraft on the Engineering screen, many of which require some extra work now the "classic" base update changed the way Hangars worked.
The goal for V8 is therefore to literally have the air combat from the first Xenonauts in the second game as a starting point to test our improvements. We'll probably chuck the same planes and weapons in the game with the same stats, and fit them into the tech tree in roughly the same place, and do the same for the UFO stats. This will make it easier for both us as the developers and you as the community to spot missing features or things that aren't working properly, and it also ensures that the strategy layer has reasonable balance / progression to allow us to test the new features we're planning to experiment with in future builds:
Interceptor Components: on the Aircraft screen there are additional slots for new types of equipment that did not appear in the first Xenonauts (armour, engines). One of the main things I want to experiment with is to have fewer types of interceptor but more possible upgrades, making the tech tree more interesting ensuring each type of interceptor can potentially stay relevant for longer.
As an aside, it might be interesting to give each aircraft type a Power stat and have the various weapons, engines and armour types draw a certain amount of power. So even basic aircraft can still use highly advanced equipment but can support less of it than the more advanced fighters.
Also, if much of the cost of an aircraft comes from its components rather than the aircraft itself, we could re-implement permadeath for the aircraft itself but make most of the equipment recoverable when a plane is shot down.
Clouds: these would provide cover on the battlefield and the amount and position of them would be randomised each battle. The idea is that combatants can move through clouds freely but they would block the fire arcs of weapons (and missiles wouldn't make course adjustments while flying through them).
Hit / Evade Chances: this an experimental change we're going to try, where combatants have % Evade scores and weapons have % Accuracy scores and Evade modifiers. The Evade roll will no longer be manually triggered and will just play an evade animation (without moving the plane laterally) when an Evade occurs. We'll see if this improves the game and if not we'll return to the old system where weapons would always hit if in range.
The % Accuracy on weapons is somewhat required if we're going to add Pilots to the game, as the obvious thing for pilots to do as they gain experience is provide an Accuracy bonus to their weapons and an Evade bonus to their interceptor. The same is true for upgrades like targeting computers or so forth; in the old X1 air combat there's just not many variables to play with and that limits the equipment and upgrade choices we can give the player.
Relative Battlefields: in X1 the boundaries of the battlefield are set at the start of the combat, but in X2 the boundaries will always be a fixed distance from the main UFO. This will allow us to set some combats up as a chase where the UFO is trying to get far enough away from your planes to push them off the edge of the map, while peppering your pursuing interceptors with fire from a rotating turret weapon (or relying on their escorts to cover for them). It's not a huge thing but in X1 literally every UFO would just turn and fly towards your interceptors so it'd be nice if in X2 some UFOs tried something a little different.
Special Equipment: we'll also likely be experimenting with some other types of equipment that weren't in X1, such as turret weapons that are capable of rotating their fire arcs, or shields. Not sure how many will provide practical but we've got a few ideas!
The main intention of these changes is to add a bit more variety to the air combat. One of the problems in X1 was that a combat featuring a particular UFO versus a particular combination of interceptors would almost always play out the same way every time, and there's a few things we can do to mitigate this. The addition of clouds means that the battlefield itself may cause the tactics to be different in different battles, and making weapons use % hit rolls should also ensure a bit more variation (e.g. a combat may play out quite differently if a long range volley of missiles at the start of combat scores 4 hits compared to if it scores 2 hits).
Depending on how the combat changes play out, I think the strategic side of the air combat may also become more complex and interesting. In X1 you were continually building steadily more advanced planes and getting rid of the older models once they became irrelevant, but if specific aircraft gain combat experience through a pilot system and are also more upgradeable than before then I can see more interesting choices becoming available to the player. Do you replace your experienced starting interceptors as soon as a better interceptor becomes available, or do you give them some upgrades and keep them around? Or just play aggressively with them until they get shot down, and then replace them? Etc.
What happened to the turn-based air combat model?
Up until V7 the game featured a turn-based air combat model. The plan was to add increasing complexity to this turn-based system until we got something that was complex enough to be fun, but was ideally a bit faster-paced than the X1 air combat and used a more similar skillset to the rest of the game.
The tun-based air combat in the public builds never got to the stage where it became fun. After the last iteration it was obvious that air combat needed proper 2D unit movement (rather than just 1D moving forwards / backwards) if it was to be interesting enough to support the more complex strategy layer that Xenonauts has compared to XCOM or classic X-Com. With overly simple air combat not only are the interceptions more boring, there's also less scope for research and UFO behaviour on the rest of the strategy layer too.
Unfortunately, when we set to work implementing this it became clear that trying to handle complex 2D movement in a fast-paced way was going to be impractical in a turn-based system. Obviously asking players to issue orders to all of their planes every few seconds wasn't an option as every combat would take hours, so we instead developed an "automated" move system based on auto-calculated moves towards your target enemy unit (or movement waypoint). We were hoping it would provide a realtime feel while retaining the turn-based system under the hood, but in practice it didn't work well - it was difficult for the user to understand what was going on and it didn't feel as natural or responsive as the X1 realtime system.
This is a bit of a shame, as the turn-based system we had planned had been paper prototyped and worked rather well as a board game. But if the fundamental building blocks of the system don't translate well onto the screen, there's point pursuing it further - it seems like we've taken the turn-based model as far as it could go. The best thing to do would just be to pluck out some of the interesting systems and merge them into the X1 realtime system.
I certainly think there's some scope to do this. Ideally, I want to try and minimise the amount of time players have to spend pausing / unpausing to try and pick the optimal split-second to do something (like rolling their planes to dodge incoming fire), so making Evasion auto-trigger on a % roll may help a lot here. Adding more variety to the air combat in general should also improve the experience and replayability for everyone, and new ideas such as clouds and the interceptor components actually work equally well under the old X1 realtime system as they do in the current X2 turn-based system.
When development began I couldn't see many improvements that could be made to the X1 air combat, which was one of the reasons I was reluctant to use the same system - I felt like I'd be serving up exactly the same thing all over again. After all this experimentation I'm now pretty sure the air combat can be improved, and it's just a question of whether we can improve things a little (by adding clouds, relative battlefields etc) or if we can improve things a lot (by getting hit chances / components / pilots to work).
Perhaps if I spent a few more months working on the turn-based system we'd make some kind of breakthrough ... but the game is now approaching Early Access and we need to make a final decision on what system we want to use because the uncertainty is holding back the strategy layer. It's a pretty simple decision; the X1 realtime system currently works better than the X2 turn-based system does, so we'll be going with the X1 system.
Anyway, I'm sure some people are going to be very happy with this change and I'm sure some other people will be a bit disappointed. I can understand both viewpoints, but really the most important thing here is that a decision has been made and in the next build we should be able to start balancing and properly playing the strategy layer. Hopefully that at least is something everyone can get excited about!
Charon 238
Woaw, what a change . And i thought the turn based combat was set in stone.
@Coffee Potato @Dagar Where them gang at ? We gotta discuss this.
Ok, this is going to be a long one, so sit down, sip your tea and relax.
Clouds:
Great Idea ! This reminds of the different clouds in Star Trek Armada 2.
Metreon Nebula (red): Deals Damage as long as the unit is in it.
Cerulean Nebula (blue). Deactivates Shields and saps power
Metaphasic Nebula(green): Positive influence by hastening repair rate
Radioactive Nebula (yellow): kills crew.
Tachyon Nebula: no special effect.
Modular Components:
@Chris Let me be frank. Just copy Space Pirates and Zombies 1 down to the last byte. They are on top of their game. And here it is:
Lets start from the top.
Every ship has a hull, some can equipt armour, and all can equipt shields.
Hull: Basic Ship hp.
Armour: decreases damage by a flat amount. Heavier armour makes an aircraft slower.
Shields: Every ship can have a shield. This ranges from junk, over standard, to either shields which quickly recharge with little protective power, to big slowly reloading shields.
The offensive power is divided into:
Cannons: Your usual "throw stuff into the face of your enemy" weapon. Good against armour.
Missiles: Long range and autohoming. Good vs hull
Torpedos: Good against everything it hits. Slow and low turn rate.
Every Ship has support modules which can be differently outifitted.
Every support modules boosts another thing in a different way.
Engine: Boosts speed.
Shield: Boosts max shield and recharge rate.
Reactor: Increases max energy and recharge rate
Cannon/Missile/Torpedo: Boost Damage/Range/Rate of Fire/Recharge Speed.
All ship types have different amount of weapon and support slots, making them different and distinctive in their role. But you can also try to use something which it is absolutely not meant for.
Pilots:
There are fleet wide Commander/Pilot classes which give certain boni like higher Damage/Range/Recharge Rate/Speed/Turn Rate/Shield.
I think a system where you put commanding officers in bases to give a bonus to the there stationed aircraft would be better than an individual pilot flying an individual plane. OR if you want people to grow attached to the pilots you can make them gain experience and gain random perks with each level up.
What do we do about the people who arent on the reaction side of things ?
I personally think that most of the stress people had in X1 was trying to control 3 (!) planes at once. Even for me its something which can be quite taxing, let alone those people who dont posses my level of concentration.
I suggest that you could reduce the stress level by assisting the player with an AI for all aircraft which the player currently doesnt control ( Just like SPAZ 1 does it). It doesnt have to be super intelligent, just things like "Attack X" or "Hold position at Y". Making them automatically dodge incoming fire, or giving them the command to stay at a certain range, in a certain (dead) angle of the UFO. This could leave the player with a way more immersed feeling of not being the only intelligent being around, while not stressing out about having to make 3 different decisions for 3 diferent planes. Focusing on 1 thing takes the stress out of things.
Lets recap.
@Charon That sounds friggin awesome, not gonna lie! Also, I'd love to discuss more on the recent version, but I can't play it yet, the Xsolla branch is still on 1.67, so no clue what the new stuff is like.
Personally, I wonder if a near perfected mini version of the above is the system FTL used. Just points distributed around different systems that allowed for different things to be powered. Like a Burst 3 and Glaive beam might one-shot the last boss, but no one in their right mind is going to risk a build that can get ruined by a single shot on the engines. (Brief primer: Every room type could have 3-8 Maximum bars in it, getting hit took 1 away until it could be repaired, EMP temporarily disabled them, and each piece of equipment took a different amount of power to use. So the above example used 2 weapons that took 4 power each, but with a max of 8, would lose half their firepower from a single shot that got past their shields). I think X1 was a dang close approximation of it, with a lot less RNG and detail.
Nah, I've always said that I was willing to change my mind on the turn-based system. I just said I wasn't willing to change my mind on it until I'd tested it as much as was feasible (which I now have). I do still think there are some fundamental flaws in the X1 system so I'm a bit frustrated that I wasn't able to come up with something better, but there's no point being stubborn about it or trying to force change for the sake of change.
That said, the one design aim I want to make clear before this discussion gets going is that I don't want to do anything that makes the air combat much slower than it already is. Having the player spend a few extra minutes tinkering with the loadout of their planes to see if they can fit a laser cannon on their Falcon without having to take the shield generator off is something I'm happy with, but having the actual combat require more micromanagement or having to swap out the pilots / tactics of your aircraft before you launch each mission is not. The "skill" should ideally be in creating loadouts and giving your planes general orders, rather than specifically micromanaging the behaviour of each aircraft during combat.
@Charon thanks for the thoughts. I'm not sure if you're advocating for special types of clouds there, but I think we'll probably just stick with the one type. I don't think the system is complex enough to support multiple types of cloud with different effects even if special magic clouds made logical sense.
The SPAZ component system you linked uses the same fundamental ideas as what I have in mind, but it seems way too complicated - although what you posted in your images lower down is a bit closer to what I envisioned. Anyway the danger with adding too much content to the air war is that it completely overwhelms the rest of the game and that's definitely something I want to avoid (also the available weapon slots have to align with what can realistically be shown in the Air Combat UI for each plane), however the component / slot system is pretty modular and modders can make something crazy complex if they want. The only limitation right now is that all planes share the same selection of slots, but that may well change in the future.
With regards to pilots I'm just thinking that each aircraft gains experience in combat and can level up perhaps three or five times, and gains +Accuracy on its weapons and +Evade on the plane. The pilot isn't seperable from the plane and the pilot is killed if the plane is shot down. It's a fairly simple system but anything more complex is going to add an extra layer of complexity to the UI, and there's already going to be a lot more to display with the component system.
Yes, some randomisation in the equipment of UFOs is something we're considering. In terms of the UFO goals in combat, I think you're going to struggle to have something like "deliver a supply run" or "terrorise a city" happen within the air combat - those are things that happen on the Geoscape. For that sorta stuff to be interesting you'd probably need a fixed battlefield with multiple UFOs and NPC air forces and defence turrets and stuff, otherwise your "choice" is always going to be to fly towards the UFO as fast as possible and shoot it down just like it is in all of the other interception missions. And that's probably beyond scope for vanilla X2.
Max_Caine 111
I see an issue arising from what has been discussed. Real-time combat requires a certain quickness of thought and responsive controls. X1 did not have responsive controls, so the quickness of thought might be there but you had to pause/unpause because the controls did not, perhaps could not respond in a timely manner to unfolding events. That fundamental issue needs to be addressed for X2 if you want to prevent pause/unpause issues.
To help address that issue, I think UFOs might take a leaf from shmups. They could telegraph their more powerful attacks (e.g. plasma cannons powering up), identify which aircraft is currently targetted by the UFO, have attacks which have predictable patterns (e.g. flak cannons producing death clouds in a predictable manner) and even perhaps have a slow time feature where everything runs at 1/4 speed instead of being paused.
TrashMan 78
Storm clouds - may push the plane in a random direction, may cause missiles to loose lock (if lighting storm cloud).
Ground AA - area where UFO will take damage if it flies (or is chased) into
Things like mountain terrain, low terran, over sea having different benefits - flying over the mountains/hills reduces speed, but increases evasion.
Watching any of the DCS videos by the Grim Reapers is very informative on how dogfighting works
Ninothree 118
Squaddie
On 9/9/2019 at 8:23 PM, Chris said:
The "skill" should ideally be in creating loadouts
This reminds me a bit of Spore. In the Cell stage you attach parts to your body as you evolve - the location/orientation of those parts then determines their use in battle. I can see that happening with weapon placements, that you can position their fire cones with a fair degree of freedom to then match your play style. e.g. dual cannons overlapping in front (aggressive, chasing), or side mounted (defensive, but maybe the weight affects your dodge %). Similarly, the location of shield generators / armour plating could be a thing. As well, if these things were mixed up on UFOs then no two dogfights need be the same.
I definitely agree about keeping aircraft in use for longer. The idea of sunk costs that are going to be discarded always seems pain in strategy games.
After rereading it, I'm all for power and skill rolls, it worked great for FTL, and that remains my jam to this day.
Jean-Luc 16
On 9/12/2019 at 10:07 AM, TrashMan said:
These are good ideas for "realistic" battlefield effects. Different types of weather, strong winds/turbulence, even advanced technology that allows both aliens and, later, humans to create , change (electrifying clouds a la Flash Gordon for example) or remove "hazard areas" during air combat.
Dagar 51
Finally able to get at this again, but short on time, so here it is:
I would have liked a turn-based system better for all the players who cannot or do not want to handle the stress of quick decision making in an essentially turn-based game. Personally, I am fine with the X1 system.
As for effects, you should always set your goal to making systems as elegant as possible, i.e. easy to learn, good to use all over the game in certain situations and an option to consider all around. Thinking about the clouds, I feel you should go the step further and allow UFOs and later planes to generate their own clouds, and also to develop weapons that are immune (or at least resistant) to the cloud cover mechanism. This could lead to a nice X-Division style arms race between you and the Xenos. And the same should apply to everything you put into the air combat system. Have autoturrets on ships? Cool, let's also be able to drop them on hovering platforms in style the style of air mines.
The enemy behaviour system is giving me headaches: Having the enemy dynamically flee can lead to frustration on the player's side, so you have to be careful what to bring into there.
Finally: make pilots separate from planes! They could lose some XP when transitioning to a newer model, so your interesting decision would be preserved. You could also add simulators that could mitigate that to some extent.
GrumpyMel 6
Is chaff or flares going to be an equipment option? It might make an interesting tactical option for combat if planes/ufo's had a limited quantity of decoys they could deploy against homing attacks. Maybe have an options slot that is configurable for a range of equipment. You could put extra weapons/missles in there, extra fuel tank, improved afterburner for a bigger bump in tactical speed, or ECM, ECCM packages. Would be a way to add more variety to the planes, as you could configure them differently for different sorts of missions. Having consumables for ECM, might give the player some tactical considerations. Do you want to decoy the small fast moving missle that you have less chance of avoiding otherwise but will do less damage or the big, slow moving torpedo that you can probably outrun if you turn away from, but will obliterate you if it hits?
6 hours ago, GrumpyMel said:
Anti missile systems worked awesome for XDiv.
On ‎9‎/‎6‎/‎2019 at 11:15 AM, Chris said:
I certainly think there's some scope to do this. Ideally, I want to try and minimise the amount of time players have to spend pausing / unpausing to try and pick the optimal split-second to do something (like rolling their planes to dodge incoming fire), so making Evasion auto-trigger on a % roll may help a lot here.
I think the best weapon to handle this is to have real-time with FIXED pauses. The game auto-pauses in fixed intervals and you can give/change orders before continuing.
This removes split-second managment, but retains the flow of combat. Check out Birth of the Federation combat on YouTube.
I had a little look at Birth of the Federation. It seems interesting. I like the idea of a turnbased/realtime meld.
From what the top post says, Chris is looking for something that doesn't involve much micromanagement in the interception mini-game. It has got to be smooth. The idea being that you push all the management towards creating your aircrafts' loadouts in the base management screen. Essentially, the choice of loadouts are the key to this phase of the game, not your orchestration of the dogfight. In Xenonauts, tactics happen on the ground. Ultimately, when a wave of UFOs launches you want excitement (stuff is gonna happen), but you don't want tedium (fighting a long series of repetitive aerial battles). In my mind, it should be almost cinematic.
Design-wise (IMO) there are aspects of a game which can be a grind (and some are rewardingly so), but shooting down UFOs isn't one of them. As we've experienced in X1, the minigame is fundamentally limited due to a lack of variables. As a minigame, it always will be limited (unless it gets enriched to the levels Charon suggests above). In its current place, the airgame phase shouldn't require a lot of clicks to get through. For what its worth, my vote would be to expand the airgame to something on par with ground combat. But as that isn't going to happen, I reckon it is most constructive to think about how to renovate the X1 system to make it as smooth as possible. Working from the assumption that you've got to issue your pilots some orders, I think the most unnecessary ones are actually to do with movement. If you can simplify the process of clicking where you want the plane to fly, the whole dogfight becomes much more streamlined. Keep the 2D field of combat, but strip out the aspect of clicking on the radar screen to direct the fighters. Reduce the player input to some basic orders like which enemy to engage, what formation to fly, and how much damage to take before breaking off. That way, the majority of success is leveraged with the decision of the loadouts, and the phase of the game where the action happens is still exciting, but ultimately not determined by the players reactions.
Mirhawk 1
I rather like Charon's thoughts above on how the experience of the pilots themselves is not as important as the air wing as a whole.
You could work this as readiness value for each airbase as a whole. When plane is shot down your value goes down as they will be replaced with a less experienced pilot, whereas successful missions increase it as your pilots and ground crew become better.
At certain readiness thresholds you could have skill tree abilities for both the ground crew and the pilots that you could pick such as quicker refueling or slightly longer range for cannon weapons. Also higher readiness could translate directly into higher accuracy and evasion as well.
You could even transfer readiness between bases to bolster a bad base or one that recently took a lot of casualty's. A ten percent transfer could be explained as you just sent them a couple good pilots and a few experienced technicians.
Also as an aside it would be cool if there were other aircraft in the combat zone. It would spice it up a bit if there were civilian craft that you could try to bait the et's away from, or military craft from the local government that could try and assist you.
Gauddlike 17
I really disliked the X1 air combat game, so much so that after the first couple of playthroughs I autoresolved every fight. I go back to X1 every few months but I haven't played an air combat in years. I found controlling the aircraft an exercise in frustration, the UI was terrible, the graphics were eye melting, and worst of all the whole process was tedious and and took me completely out of the flow of the rest of the game.
Having got that out of the way I am looking forward to seeing how this can be improved for the new game. I feel that having more variation on the loadout of your fighters will add an interesting aspect to the game that was lacking from the original. I also like Chris suggestion that the craft be treated more like ground troops in the way the basic airframe can be destroyed but the expensive and time consuming to produce equipment can be saved to be reused. I found losing an aircraft or squadron to be such a massive setback in X1. That it happened in a part of the game I already didn't enjoy was my primary reason for giving up on a campaign.
I would prefer pilots to be a separate entity to their aircraft purely because developing some kind of attachment to your soldiers was always a big part of this type of game to me. If I find I have a favourite fighter/pilot that has pulled off a bunch of near miraculous wins and narrow escapes I would feel a bit of a traitor dropping them for a shiny new plane/pilot combo just because I need a power boost.
My main feeling on an improvement to the air combat would be for the UFO AI to be improved and for your aircraft to have access to the same. I would much prefer to give orders to the aircraft and leave them to execute them than to have to frantically click or spam pause to give individual instructions. I doubt it is in the scope of what Chris is envisioning but giving a plane a target and telling it to attack aggressively (straight in to optimal range, fire all weapons as able), attack cautiously (stay at longer range, run in to fire missiles then retreat out of range), jam this target, stay out of range etc and then for its pilot to actually do it could feel significantly better. Even Battlefleet Gothic Armada with its fairly basic AI feels like the ship captains can follow orders and you only really need to pause to respond to something really unexpected or to issue a special command.
Ruggerman 37
I would prefer not to do air combat, and only do Auto resolve every fight. I can't see why there could not be missile sites doted around the globe, with radar, and then advance to engage in ground combat, with the downed UFO.
On ‎9‎/‎20‎/‎2019 at 8:47 PM, Ninothree said:
Agreed. This is one of the reason I suggested BOTF system. It looks/feels cinematic, allows for more variables, and flows rather fast.
But if equipment is 99% of air combat, there's no need to any player input at all, and it can just be auto-calced.
drages 72
Nice to hear to have the real time x1 style.
I just want to have different hangar types for possible bigger planes and bigger spaceship types. I would like to fight against ufo battleship with my big ship not just little planes.
Modable weapon slots would be great.
To be honest, xcom 3 got great and simple plane inventory. It could be used very easily. So energy shields and invisibility would be cool. Tbh game should have power shields for both air and ground like xcom 3 did.
Air game should be simple and mostly about stats rather then reflexes. But creating your plane with all the things, armor, weapons, engines, special stuff and having pilots would be nice addition to the strategic theme. Don't simplify that part or at least make it Modable so ppl can have choice.
Full Armored Core levels of customization when? I want Star trek Shields, blink dodges, and have the option to put decals on every square millimeter of that bad boy.
Edited October 1, 2019 by Coffee Potato
Eviscerator 0
Honestly, for me most of the micromanagement in the X1 airgame was selecting/deselecting missiles and cannons to make sure I wasn't wasting torpedoes on fighters, or shooting all my small missiles at battleships.
I'm not sure of a solution beyond being able to set engagement parameters such as 'fire x-type weapon at y-type target' as a sort of standing orders or common sense for your pilots. Of course, you can countermand the orders, but that's your choice as the commander and not constantly clicking and clicking and clicking in every engagement.
Or maybe just getting rid of missiles entirely like XCOM did in the mid to late airgame and using laser cannons and railguns that don't have arbitrary short ranges?
stewpidbear 14
If an aircraft is shot down shouldn't there be a chance that the pilot ejected? Perhaps new missions to rescue downed pilots?
4 hours ago, stewpidbear said:
Sure. I get the impression though that Goldhawk do not want to introduce pilots as a separate entity from planes. I'd like to see that, but at the same time, I don't mind too much, that sounds like a very easily implementable concept as a mod (given that GH want to make X2 as moddable as possible).
John Knee 1
Judging from the recent set of postings from people, I suspect quite a few people didn't know about this thread until the recent kickstarter e-mail (myself included). Looking at the date of the original post, I suspect Goldhawk are already a decent way into programming the changes outlined. Despite this, I will add my own comments albeit late. In context of my views, I haven't played the original and have only periodically played the new game so by no means an expert - hence maybe a little bit of a wishlist on my part but... Most of the following is on the assumption that it is still turn based although quite a bit would work in a non-turn based system.
Interceptor Components
"One of the main things I want to experiment with is to have fewer types of interceptor" - the common idea is to have three types of interceptors consisting of
1) a small, highly manoeuvrable craft that is hard to hit but is limited on the amount of weapons it can carry.
2) a heavy "bomber" that is slower, less manoeuvrable but can carry heavier hitting payloads
3) the "middle of the road" craft.
From a tactical point of view, you may choose a heavy bomber with a couple of the smaller aircraft who do the closing down and acting as a decoy while the heavy aircraft gets into range. This may play out interestingly with "This will allow us to set some combats up as a chase where the UFO is trying to get far enough away from your planes to push them off the edge of the map". Depending on what UFOs you identify as intercepting, you might well choose a different combination of interceptors.
One idea to put forth is the idea of having a two pilot interceptor where you have one pilot responsible for flying and the other for weapons. This would be an interesting variation if you go down the path of pilots with individual skills - you might get a better impact from a good pilot and gunner flying together but eggs in one basket etc.
"The idea is that combatants can move through clouds freely but they would block the fire arcs of weapons (and missiles wouldn't make course adjustments while flying through them)." - this makes no narrative sense. Unless the missile is TV-Optic guided like a Maverick anti-tank missile, there is no reason why a heat seeking or radar guided missile would get confused by a cloud. What makes narrative sense would be to classify the clouds in the following way:
Light clouds - has a relative small aiming penalty when firing cannons or any weapon where the pilot would presumably put the target in the cross hairs and pull a trigger. Missile act as normal
Heavy Clouds - can be used to hide in with high aiming penalties when firing cannons to the point you 'd probably avoid using such weapons.
Thunder Storm - RARE. As per heavy clouds but with the added penalty of playing havoc with the electronics and aiming systems of missiles. There could be visual clue that a bolt of lighting will happen in the next turn which may alter what you planned to do next.
"we'll also likely be experimenting with some other types of equipment that weren't in X1, such as turret weapons that are capable of rotating their fire arcs, or shields." - arrrrrrrgh. Turrets on a plane, god no. Logically these turrets are computer controlled so would either be 100% accurate and OPed or as bad as the turrets in Star Wars or the original Battlestar Gallatica which despite being radar and computer controlled never actually hit anything except for its own ship and only actually hit when the craft flew directly at the turret (and even then took several shots before it hit). Special equipment I'd like to see (and I'm not an expert so some of these might already exist)
External fuel tanks to increase the range of crafts.
JATO rockets - these are used in real lift to help heavy aircrafts take off on shortish runways. In X2 then this would mean the aircraft could go from the back of the screen to 2/3rd up and enable it to be in range for its cannons in one turn. Each rocket is usable once per mission.
Parachute - kind of an anti-JATO rocket that means an aircraft close behind the UFO and in danger of being destroyed can rapidly lose speed and drop out of the battle. Usable once per mission and when used almost guarantees you won't be hit upon retreating.
"Fake Damage" pod. In WW2, some submarines had compartments which when released would see a load of oil and metal float to the surface and to fake a sinking so that the destroyers above would stop dropping charges and leave. Maybe a device that fakes damage to the aircraft so that the enemy assumes is fatally damaged and will target a different aircraft instead?
Cloud Projector - if you are going to have clouds then you could have a projector that shines a light of your ship in front of you and "project" an image of a ship in front of you. This might fool some types of enemy weapons.
"With regards to pilots I'm just thinking that each aircraft gains experience in combat and can level up perhaps three or five times, and gains +Accuracy on its weapons and +Evade on the plane. " - this doesn't make narrative sense. Why would an aircraft get better because it survived a mission?? It would make sense to keep the aircraft itself remain the same (with the same default characteristics if you copied the 3 aircraft types I mentioned earlier) but the pilots improve. As per the soldiers you could have a skill for
flying (modifier when avoiding attacks),
shooting (modifier for shooting accuracy - different skill for missiles and cannons?)
Stamina (less important in a fight, but pilots need to sleep and recover between flights and the better the stamina the quicker to be at 100% when next flying)
Bravery which determines if a pilot will fire missiles at the maximum range or is prepared to get in closer when the odds of hitting is maximised.
On top of this, some pilots might get random "specials" such as:
Quick reactions - bonus to evasion
20/20 Vision - not impacted by aiming penalties in light clouds (see prior comments)
Mechanic - is able to make minor repairs in flight and therefore recover a small amount of aircraft health (repairs capped so not OP)
Short Sleeper - suffers from Short Sleeper Syndrome which means they need minimal sleep to function.
Linking together all my air module comments, upon identifying a UFO in the sky, the first bit of strategy is to decide on the aircraft type (three small aircrafts to take on a drone or scout type ship or some heavy hitters against a bit battleship?), the type of pilots (so you might use one small aircraft as a decoy with a Quick Reaction pilot with a couple of big hitters) and then have a decision on weapon make up.
"Obviously asking players to issue orders to all of their planes every few seconds wasn't an option as every combat would take hours"
Here is an idea that would make it work - you only actively control a single fighter and at the beginning of the fight at turn zero you issue orders of how you'd want the rest to fight. So if you are fighter one (on the left hand side) you can select fighter 2 (on the right hand side) and give the order:
FOLLOW ME + IMITATE
with such an order, when you move your fighter forward and shoot a missile, fighter 2 will also move forward and shot a missile. If in the next turn you hold position and shoot your cannons, then fighter two will also hold position and shot their cannons. Other variations could be:
FOLLOW ME + FIRE AT WILL - will copy your position but will shoot if a weapon is in range.
FOLLOW ME + FIRE AT OPTIMUM RANGE - will copy your position but will shoot once once it has moved a block closer than the maximum range of the weapon.
For fighter three (in the middle of your fighters) who might be a heavy hitting fighter, then the order might be:
SHOOT AT MAXIMUM RANGE
at which point it will advance until in missile range and will fire off missiles each turn until it has run out - at which point it'll advance until it gets into range of it's next weapon (say cannons). Other options could be
ADVANCE AND SHOOT - fighter will keep moving forward and will use the most powerful weapon that is in range
ADVANCE AS DECOY (PURE) - fighter will make itself the most advanced fighter and will adopt evasive manoeuvres (bonus to evasion - maybe the ship could do a wiggling motion to reflect this)
ADVANCE AS DECOY (POT SHOT) - if the enemy shot at a different fighter in the previous turn, it'll fire a weapon to get the enemy ship's attention that round.
KAMIKAZE - the fighter is a shot away from dying and is too close to run away then why not Thunderchild it heroically? And congratulations you get the "Ram Raid" achievement.
There are other simple commands you can do - "ATTACK NEAREST" if there are multiple enemies etc. Once you have selected the order then the computer will carry it out while you focus on just your craft. Of course there is always the option to radio new orders (that'll come into effect the follow turn)
The main complaint is the need to constantly give three sets of (probably identical) orders every turn *yawn*. There is nothing to stop you from creating a set of default battle plans in the hanger that you can select based at the start of the battle.
"If an aircraft is shot down shouldn't there be a chance that the pilot ejected? Perhaps new missions to rescue downed pilots"?
(copied from someone else's post) If Chris isn't into the idea of you wanting to rescue your downed pilots in principle then it would be a great one off side mission where the reward is one kick ass elite pilot levelled to however far you are in the game at the time.
Edit: an idea I forgot to add:
Camouflage painting of your aircrafts.
If have a choice of paint colour schemes for your aircraft:
Sandy - makes the fighter harder to see and hit if over a desert
Blue - makes fighter harder to see and hit if over the ocean
Night Sky Black - make fighter harder to see and hit if fighting at night.
Snow White - makes fighter harder to see and hit if fighting over the north or south pole.
Green / Brown - makes fighter harder to see and hit if fighting over the Amazon rain forest etc.
Depending on where your base is might see your fighters doing more combat over certain terrains more so there might be a minor advantage in your colour scheme, although you will probably be punished if painted in Snow White at night and vice versa.
Edited October 2, 2019 by John Knee
Here's a thought. The idea is to have a real-time combat system that's sufficiently simplified that it's a minigame not a full game in its own right, while not being a stop/start/stop/start like it was in X1 and have sufficient customisability to make each UFO interesting.
Why not rip off the real time system from the Final Fantasy series? The Final Fantasy RTS system has seen a number of evolutions through the years, but at its heart is a real-time system that gave you time to think about what you're doing, and nowhere was that more evident than in FF VII. You could have the UFO on the right-hand side of the screen fleeing and the Xenonaut fighters on the left-hand side of the screen pursuing the UFO so while the fight is static, it looks as if everything is in motion. When the Active Time Bar for a fighter fills up you can issue it offensive instructions (such as what weapon to use or where to target). When the Active Time Bar for the UFO fills up, you get the chance to issue a defensive instruction (such as where to evade) to the plane or planes that the UFO is targeting.