Talk:Heavy Cannon vs Auto Cannon

Jasonred: During the early part of the game, the most common enemies (the only enemies?) are Sectoids. Since a sectoid is so very delicate, even a near miss from a AC-HE round can kill it, thus changing the kill probabilities a bit. The HC has higher firepower per shot, but a great deal is "overkill" in this case.

I don't think the above is true so I've moved it here for discussion.

For direct fire / direct hits, there is no overkill. Because direct fire damage is 0-200%, for unarmoured targets the kill probability is linearly proportional to base damage (where Health < 2*Dmg). For armoured targets, kill probability rises better than linearly with base damage. So there is no overkill.

But you are talking about HE area damage (near misses). I actually did not model near miss effects in my firepower calculations. In theory there is an overkill factor in area damage, whenever 0.5 * Base Damage is > (Armour + Health). But in practice, even weedy Sectoids are not this weak. Keep in mind a near miss is 10 or 20 base damage less than a direct hit. So in practice, area HE kill probability for these weapons has no overkill and is better than linear with base damage.

If we compare AC and HC as HE area weapons, the HC has a greater lethality over a greater area with a greater accuracy. I have not done the sums but my gut feel is that it will outweigh the better fire rate of AC auto.

By the way, the firepower advantage I'm quoting is not per-shot but per unit of time or per TU. Also, Floaters are quite common in the early game, and the terror units associated with both Floaters and Sectoids will be encountered toward the end of the first month, when AC and HC are still state-of-the-art weapons.

Spike 06:13, 27 February 2009 (CST)

Overkill limit

Quick calculation: With health of 30 and under armour of 2, you need an explosive power at least > 75 to get any overkill on a Sectoid with a near miss. AC-HE is 44, HC-HE is 52, Grenade is 50. By overkill I mean that the minimum damage is enough to kill, therefore the kill probability stops rising with the base damage because it is already 100%. Spike 06:51, 27 February 2009 (CST)

Kill Modelling

Well, that's why I rely on you guys who have all this software which can be used for kill modelling and such. MY proposal: test and compare Autofire and snap shot for both AC and HC. I'm not certain, but I'm under the impression that the the AC-HE on autofire has the best chance of killing a medium distance sectoid in one attack. And also the best chance of killing in 1 turn.

The high tech software we use generally involves pen, paper and maybe a calculator. But I guess those with access to spreadsheets and other analytical software do certainly have a clear advantage! Heh.

For highly inaccurate attacks over a great range, auto attacks tend to be more reliable compared to single attacks in general. Even if you were firing at a resulting accuracy level of 10%, your chances of hitting at least once tend to be greater with an auto attack than a snap or aim shot. Snap an aimed shots on the other hand work best at high accuracy levels for medium to long ranges. That's where both of the cannon types lever their advantage.

The AC-HE on auto does have one thing that goes heavily against it though: Loot destruction. Assume that the alien was killed on the first hit, the remaining two hits would then blow up the items on the ground unless they missed, which can happen with the first or second direct hit on the first three primary alien races you encounter.

The lower damage of the auto-cannon is an advantage later on once you get power suit or flying suits. -NKF 11:29, 27 February 2009 (CST)

NKF: The most valuable part of any alien's gear is their weapon, which the Autocannon-HE lacks the power to destroy. It can destroy clips, grenades, the corpse, and either of the launcher weapons, but a GZ hit from the AC-HE does 44 damage against objects on the ground; the Plasma Pistol needs 45 damage to be destroyed, and the Plasma Rifle and Heavy Plasma need 50 damage. The Blaster Launcher needs 40 damage, so is safe if you botch the shot by one, and the alien corpse(26 damage or more) is safe if you botch by two or more. The rest of their gear survives at 3 or more spaces off. Arrow Quivershaft 12:12, 27 February 2009 (CST)