BtS Air Combat

[=DrJambo=]

Just wanted to say how much better air combat is now.

Firstly, the new line of air promotions make air combat fun and rewarding.

Second, it appears that it's now possible to intercept and attack enemy air units when it's your turn! Something I was always frustrated about in early versions was this inability to attack and remove enemy air units while they were on the intercept mission. Essentially, what you had to do was use enough planes to exhaust the enemy of its available interceptors. Then you could bomb to your hearts content. Tedious. Plus it was way too easy to win air superiority over the AI.

So now to a question or two:

1. Is there an advantage to being the defender in air battles? Does the intercepting unit have a greater or less chance of doing damage to the offensive plane? Is there any specific mission one has to do to engage defending aircraft, or will both striking and bombing work equally?

2. Bombers seem to have quite a good chance of doing damage to fighters. How is air combat resolved?

3. What stops fighters from having a 100 % chance of interception? Damage? If so, is it simply that a fighter at 50 % health then has a 50 % chance of intercepting?

[Solver]

Yay, thanks!

1. The advantage to being the defender is that you roll dice first, so you have a higher chance of being the one to intercept. And any mission triggers engagement equally.

2. The mechanics are pretty complex, and usually both planes get damaged when in combat. The code is as follows.

*code removed so as not to mess layout up* If anyone's interested, the relevant code is CvUnit::interceptTest() in the SDK.

3. Damage, yes. And the interception probability is indeed calculated with regards to hit points, so a fighter with 50% damage has a 50% chance of interception.

[=DrJambo=]

Not really a code monkey!

Bombers have strength 16 and fighters have strength 12. Does that mean that 1 on 1 a bomber is more likely to win?

[Solver]

I'll try to explain the code.

Whenever interception is possible (a mission is performed within the range of an interception-capable unit), a random number from 1-100 gets rolled (code monkeys: yes I know it's not technically correct, shut up ). If the number is less than the interception probability of the best interceptor, nothing will happen. With Fighters now being able to intercept at 100%, an interception will always happen with a full health Fighter defending.

Possible damage per air combat round to either plane will be the other plane's intercept probability * 50 / 100. If the other plane can't intercept, it'll just be 10.

So a Bomber attacks and a Fighter intercepts. If the Fighter is at full health, it will do 100 * 50 / 100 == 50 damage per combat round. The Bomber can't intercept, so it will do 10 damage per round.

Next, the rounds themselves are resolved, there are 5 rounds (these numbers are unmodded values). The attacking plane's odds are calculated as 100 * AttackersStrength / TotalStrength, where TotalStrength is the sum of both plane's strengths.

So a Bomber (16) attacking a Fighter (12) would mean that the Bombers odds are 100 * 16 / (12+16) == 57.

Now up to 5 combat rounds get resolved, each individually. If the attacking plane wins the round, the defender gets damaged. If the defending plane wins the round, the attacker gets damaged. In the above example, the Bomber would have a 57% chance of winning each round. If it does, the Fighter would be damaged 10%. If the Fighter wins the round (43% probability), then the Bomber will be damaged by 50%. As such, the Bomber wouldn't destroy the Fighter even if it won all 5 rounds, but the Fighter only needs to win 2 of 5 rounds to destroy the Bomber.

That's the gist of it, I hope it's clear enough.

[MoonWolf]

Often you (well, at least I) just activate a bomber stack and have them all attack a tile together (haven't tried this in BtS though, only Warlords). If you also have fighters in this stack, will the figthers attack the interceptors first (or as the code will maybe be: the interceptors will head for attacking fighters first)? Or do you have to attack with fighters first to simulate support for bombers?

Thanks for the explanations, btw, it's always interesting to get a view of the mechanics behind

[Solver]

There is no such thing as stack attack in Civ4. If you select multiple units, the computer will just automatically attack with them one-by-one, starting with those that have the best chance.

I'm not exactly sure how it would work. I assume if you select air bomb, which Fighters can't do, they'll do nothing, otherwise, it will all depend on the odds. I attack with Fighters first manually if I want to have them engage before Bombers.

[MoonWolf]

I can try to play around with something next time I play in the modern times and the AI has fighters. I'm anyway looking forward to have a decent modern game with dogfighting

[=DrJambo=]

So, let's say a fighter is attempting to intercept a enemy fighter/bomber. Now, correct me if I'm wrong here:

1. If the fighter is full strength it has a 100% chance to intercept, leading to 5 combat rounds. If it isn't at full strength then it only has a % chance of intercepting equal to its remaining strength (or is it HPs?).

Q - If the fighter fails to intercept, then the enemy fighter or bomber carries out its intended mission, right?

2. If interception occurs, then there's 5 rounds of combat. The winner of each round is decided on a roll based on the attacker's odds as calculated by: 100 * AttackersStrength / TotalStrength.

Q - Are the stated strengths in the above formula modified by how damaged a unit is similar to interception %, or, are they just based on default unit strength regardless?

[Solver]

1. If the fighter is full strength it has a 100% chance to intercept, leading to 5 combat rounds. If it isn't at full strength then it only has a % chance of intercepting equal to its remaining strength (or is it HPs?).

Yeah. Minor correction, it's not 5 combat rounds, it's up to 5 combat rounds - the attacking plane can be dead after as little as 2 rounds, in which case combat is obviously over. A half-strength Fighter has 50% chance of interception, at strength 3 of 12 it'd have 25%, etc.

Q - If the fighter fails to intercept, then the enemy fighter or bomber carries out its intended mission, right?

Exactly.

2. If interception occurs, then there's 5 rounds of combat. The winner of each round is decided on a roll based on the attacker's odds as calculated by: 100 * AttackersStrength / TotalStrength.

Q - Are the stated strengths in the above formula modified by how damaged a unit is similar to interception %, or, are they just based on default unit strength regardless?

Sorry, should have mentioned this. It's the current combat strength, taking damage into account, which is crucial to balance. That's why a near-dead Fighter won't fare well at all.

[Shrapnel12]

Is the scenario you described for air combat the same in Warlords Solver? The reason I'm asking is I was awfully annoyed when a simple fighter kept shooting down my jet fighters in Warlords. I thought that was a bit unrealistic.

[dregor]

I'm liking the expanded role of air for sure. One gripe I have is that I wish it would focus in on air combat when it goes off during the AI's turn. It can get hard to follow what all is intercepting where if there's a few different engagements going on.

I also wish Spies gained experience and levels ><

[=DrJambo=]

Shrapnel12, no, it's completely reworked it seems.

Solver, so a full strength fighter (without promotions) on an attacking mission has a 50:50 chance to win against a full strength defending fighter (without promotion).

Lastly, how does the 'ace' promotion affect the % chance to intercept? Would it make a full strength 100% chance into 75%?

[Solver]

Is the scenario you described for air combat the same in Warlords Solver? The reason I'm asking is I was awfully annoyed when a simple fighter kept shooting down my jet fighters in Warlords. I thought that was a bit unrealistic.

Not sure what it was in Warlords. Well, obviously, Fighters could only intercept once, so the system was different anyway - giving them multiple interceptions was the cornerstone of the air combat system as I envisioned it.

[Solver]

Solver, so a full strength fighter (without promotions) on an attacking mission has a 50:50 chance to win against a full strength defending fighter (without promotion).

Do I look like a calculator?

Lastly, how does the 'ace' promotion affect the % chance to intercept? Would it make a full strength 100% chance into 75%?

Ace, and all other "avoid interception" situations kick in first, before anything else. Dice are rolled to see if the unit evades (1 in 4 with Ace for Bombers, for example). If it evades, nothing else happens. So a full 100% would indeed become 75%.

[=DrJambo=]

Originally posted by Solver

Solver, so a full strength fighter (without promotions) on an attacking mission has a 50:50 chance to win against a full strength defending fighter (without promotion).

Do I look like a calculator?

Ah, so it's more complicated.

I thought the process might have been:

1. Defending fighter intercepts (100%)
2. Odds for attacker winning the first round is 100*12/24, so 50%.
3. Either way the damage done is 50 because fighters can intercept.

However, my 50:50 question was based on the premise that attacking fighters are also considered 'able to intercept' and therefore able to do more than 10 damage? Or are attacking fighters like bombers and do just 10 damage?