Turret mechanics

There are basically three things that affect your chance to hit a target with a turret-mounted weapon: range, tracking and signature resolution. This guide explains each factor in turn, and explores some of these factors' practical implications for combat. The last section summarises the support skills which can improve your gunnery.

See the page on turrets for more general information about the guns and ammunition available in Eve. The principles explained in this guide apply to all kinds of turret, but definitely do not apply to missiles, which have their own page.

If you want to read about the detailed equation controlling gunnery, go here. This guide will sometimes refer to this equation, but will (hopefully) explain how gunnery works without becoming too mathematical. Note that, broadly speaking, as your chance to hit decreases your chance of doing high-damage, good hits ('wrecking' shots, and so on) also decreases.

Range

In Eve, hitting with a turret is not quite a simple question of being either in range or out of range. Instead it depends on the concepts of optimal range and falloff. You can find figures for both of these if you hover your mouse cursor over any turret.

A gun's optimal range is the range within which, if tracking and signature resolution don't intervene -- and (see below) practically speaking they probably will -- the gun has a 100% chance to hit.

Accuracy falloff is a measure of how quickly a gun's accuracy decreases as a target moves beyond optimal range. At a gun's optimal range plus its falloff, it will have a 50% chance to hit a stationary (or large and low-traversal) target. At a gun's optimal plus twice its falloff it will have only a 1/16th chance to hit a stationary target, and it might not be worth firing at all unless you're simply trying to draw aggression from a rat, which you can do all the way out to your maximum targeting range.

So, for example, say you're firing a gun fitted which has 20km optimal range and 6km falloff at a target which is moving steadily straight away from you (zero traversal), starting at only 1km range. You will (if nothing else intervenes) always hit a target that is less than 20km (your optimal range) from you; your chance to hit will gradually decrease as your target moves between 20km and 26km (your optimal + falloff) from you, reaching 50% at 26km. By 32km (optimal + twice your falloff) your chance to hit will be down to 6.25% and decreasing.

As was mentioned in this page's introduction, your chance of dealing good, more damaging hits ('wrecking' shots that deal more damage) decreases as your chance to hit decreases in falloff. This relationship is not linear, and your chance of good hits decreases quite rapidly as you move into falloff. According to the Eve wiki at optimal + falloff, where your chance to hit is (as always assuming other factors don't intervene) 50%, you can expect something like 40%, not 50%, of your theoretical maximum DPS.

Increasing or Reducing Range

You can increase your optimal range by fitting Tracking Enhancers in your lowslots, or Tracking Computers in your midslots (particularly if you load the latter with the Optimal Range script). Tracking Enhancers also increase your falloff range (and, as the name suggests, tracking speed -- see below).

Training levels in Sharpshooter will increase your guns' optimal ranges, and Trajectory Analysis will increase their falloff ranges.

Tracking Disruptors can (despite their name) reduce their target's optimal and falloff ranges. They will do this particularly effectively if they're loaded with the Optimal Range Disruption script.

Tracking

If you 'show info' on any turret you will find it has a figure for tracking speed in its list of attributes, measured in 'rad/sec', radians per second. This tracking speed measures the maximum speed that the turret can turn as it tries to track your target.

The smaller a turret is, the faster its tracking speed will be: small autocannon, for example, track faster than medium autocannon. Short-ranged varieties of turret have better tracking than their long-ranged counterparts -- so, for example, medium pulse lasers track faster than medium beam lasers and large blasters track faster than large railguns.

In chance-to-hit calculations, your guns' tracking speed is compared against your target's angular velocity, which is also measured in radians per second. Angular velocity is a geometric concept, which can be hard to visualise.

One way to think about it is to imagine that your screen's point of view in Eve is looking out above the barrels of your turret as it looks at your target -- a turret's-eye-view, so to speak. If your target was moving quickly across your turret's point-of-view, it would have a high angular velocity, and if it was moving slowly across your turret's point-of-view it would have a low angular velocity.

If your guns' tracking speed is lower than your target's angular velocity, you're very unlikely to hit them. If your target's angular velocity is below your guns' tracking speed, your chance to hit increases. If your target's angular velocity is very much lower than your guns' tracking speed, you will have a very good chance to hit.

The speed at which a target moves across a turret's field of view doesn't depend only on the target's real velocity. The direction the target's moving in relative to the ship firing at it matters too: a ship that burns straight towards you could be quite easy to hit, regardless of its speed, because it's not moving very fast across your turrets' point-of-view. Range also affects angular velocity: a target orbiting you at 400m/s at a range of 7,000m has a much higher angular velocity than a target orbiting you at 400m/s at a range of 30km.

Note that the actual mathematics of tracking are more involved than the basic summary here. Angular velocity itself depends on transversal velocity, but it's easier to think about angular velocity since measurements of it in radians per second relate easily to the figures for gun tracking speed, which are also in radians per second. You can find a brief explanation of the differences between angular and transversal velocity here within our overview guide.

Speeding Up or Slowing Tracking

You can increase your guns' tracking speed by fitting Tracking Enhancers, or Tracking Computers (particularly if you load the latter with the Tracking Speed script).

Training levels in Motion Prediction increases your guns' tracking speed.

Tracking Disruptors, as the name suggests, can reduce their target's gun tracking speed, especially when loaded with Tracking Speed Disruption scripts.

Signature Resolution

Every ship in Eve has a signature radius (you can find a figure for yours on the fitting screen). Signature radius represents, roughly speaking, a ship's footprint on everyone else's sensors.

Here are some example signature radii:

• the Incursus (frigate) has a base sig radius of 44m
• the Caracal (cruiser) a base sig radius of 145m
• the Hurricane (battlecruiser) 240m
• the Abaddon (battleship) 470m

Base signature radii can be altered by various things: shield extenders, for example, increase your sig radius, while an active MWD boosts your sig radius by 500%. Normally when Eve players just say 'signature' they mean 'signature radius'.

All turrets have a figure for signature resolution in the Attributes tab of their show info window. Sig resolution indicates the size of target that the gun's designed to shoot, and represents, roughly speaking, the gun's ability to accurately aim at the target's sensor footprint.

(Do not confuse signature resolution with scan resolution: although scan resolution does interact with signature radius when you are locking on to a target, it's entirely separate from your guns' signature resolution and definitely does not affect gunnery.)

In the chance-to-hit calculation, the target's current sig radius is compared to the gun's sig resolution. It's not strictly accurate, but most of the time it's enough to say that when the target's sig radius is larger than the gun's sig resolution the chance to hit increases, and when the target's sig radius is smaller than the gun's sig resolution the chance to hit decreases.

In fact, what happens is that the comparison between gun signature resolution and target signature radius feeds into the tracking calculation. If the target has minimal or no angular velocity (if, for example, both ships are sitting still, or the target is flying straight towards or away from the firing ship) then the tracking calculation has very little or no effect on the chance to hit, and therefore the target's signature will be irrelevant.

This is why it is possible for a rack of battleship guns to hit a frigate for (as they say) massive damage despite the frigate's very small signature: if the frigate sits still, or burns straight towards or away from the battleship, or is at a long enough range that despite its speed it doesn't have much angular velocity from the battleship's point of view, it is toast.

Boosting or Reducing Signature Radius

Target Painters increase their target's signature radius and (as mentioned already) microwarpdrives increase a ship's sig radius by 500% when active. (Except on Interceptors, which have bonuses which reduce the sig bloom caused by MWDs.) There are implants (Halo) which reduce your ship's signature radius, but their effect probably doesn't justify their price unless you are very, very rich.

Practical Applications

Although you can add angular velocity (or transversal velocity, if you want it) as an extra column to your overview, you'll never have the time in combat to get out a calculator and run through chance-to-hit equations. There are however some tactics which let you use gunnery mechanics to your advantage.

Controlling Range

You should probably try to fight within your guns' optimal range, but be prepared to fight within your optimal + falloff range (also called 'first falloff') if you must.

Autocannon are an exception here, as they have very long falloff ranges and some Minmatar ships have specific bonuses to falloff (220mm autocannon loaded with Barrage and fitted on a Vagabond with Tracking Enhancers can theoretically have over 40km falloff, for instance). Pilots flying with autocannon should therefore feel happier about fighting in falloff.

In practice, if you're using long-ranged turrets (artillery, railguns and beam lasers) you will find that once targets get close enough within your optimal range their angular velocity will rise so much that you can't hit them. Some ways to handle small, fast, closely-orbiting targets are discussed below. Besides dealing with them once they do get close, it's worth finding a range which is within your optimal yet far enough away that the enemy are easy to track.

Although you can use tools like EFT's DPS graphs, this knowledge comes partly with experience. It's much easier to figure out against NPC rats, which always have the same characteristics while kindly heading more or less straight for you until they close into their preferred orbit range, than it is with PvP enemies.

Obviously if you find a way to pin your enemy down at a range where you can hurt them but they can't hurt you, you'll win. On the other hand, if you find yourself fighting an enemy who outranges you and can move faster than you, and you can't ameliorate either of those problems, you should consider trying to escape.

Dodging Fire

The conclusion from all the information about tracking speed and signature resolution is: when you want to avoid damage, you want your angular velocity (as your enemy sees you) to be higher than their guns' tracking speed and your signature radius to be lower than their guns' signature resolution.

Under the Guns

For new pilots who are likely to be flying small fast ships one of the key ideas that follows from this is the tactic of 'flying under the guns' of an enemy ship: orbiting them at high speed and short range so it's very hard for their guns to track your small-signature ship. (Sometimes referred to as a form of 'speed tanking' or 'sig tanking'.) Assuming you're fast and small enough to survive under the enemy's guns, the main trick is getting there in the first place: if you burn straight towards the enemy, they will probably hit you (especially if you have an active MWD).

Spiralling In

Therefore it's wise to spiral in towards the enemy. To do this:

1. Zoom in reasonably close to your ship and centre it on your enemy so that it covers up the enemy on your screen.
2. Now double-click in space halfway between your ship and the edge of the screen (in any direction).
3. Your ship will begin moving roughly towards the enemy, but not directly at them; it will also move away from its position covering the enemy ship on your screen.
4. As it does so, repeatedly realign your camera so your ship goes back to blocking your view of the enemy, and each time you do so double-click halfway between your ship and the edge of your screen again.
5. This should make you spiral around them, moving ever closer until you can orbit (hopefully safely).
6. There is no six. It burned straight towards the enemy with its MWD on and was one-shotted.
7. It might be a good idea to practice this on large NPC belt rats before trying it in PvP combat.

(Similarly, it's good not to just burn straight away from a larger enemy if you're trying to escape, though by that point in a battle you may find you're too busy to take account of your relationship to enemy tracking.)

Caveats

• Against missile ships angular velocity is irrelevant, although a small signature and high speed still help you reduce damage from missiles; if you're only facing a missile ship, you could head straight for them
• Drone ships using normal drones (not sentry drones) won't have a problem because their main damage dealing is coming from the drones, not any guns they have fitted
• Your angular velocity will be different in relation to different people: if you're safely orbiting one enemy fast and close enough that he can't hit you, another enemy who's 20km away might be able to hit you much more easily
• When you finally issue an orbit command to your ship it may change direction, possibly one which will briefly, but dramatically, reduce your angular velocity; there's a lower chance of this happening if you issue the orbit command before you reach your planned orbit range, rather than once you're already within it
• Your orbit will probably not be circular, but elliptical, with your angular velocity rising and falling as you travel around it
  • If you orbit very close to your target, your ship will fly an elliptical orbit to try to cope with the fact that your speed makes it hard for it to fly a tight orbit (afterburners will exacerbate this)
  • If your target is moving (and it probably will be) this will also produce an elliptical orbit
• Your enemy may have smartbombs, and medium and especially large smartbombs deal quickly with frigates; this is why rookie tacklers are advised to orbit large ships outside smartbomb range

There are also a number of tactics and modules that larger ships can use to solve tracking problems: these are the subject of the next section.

Hitting Smaller, Faster Things

From the point of view of a large ship struggling to hit small fast ships which are orbiting close to it, either in PvP or PvE, the solution is to reduce your target's angular velocity and/or increase their signature. If you can almost entirely reduce their angular velocity you won't need to worry about increasing their signature because (as described above) the effects of signature radius and resolution affect the tracking calculation within the chance to hit calculation, not the chance to hit calculation directly.

Modules

Stasis Webifiers are a common solution. T1 webs reduce their target's speed by 50%, T2 webs by 60% (overheating a webifier increases its range, which can help you snag a player who's dancing just beyond web range). Target Painters will help, though probably not as much. You can also try boosting the tracking speed of your guns with Tracking Computers and Tracking Enhancers.

Maneuvers

If the size and speed difference between you and your target is not so great, you may be able to reduce their angular velocity simply by maneuvering.

• You can try burning away from them -- hopefully encouraging them to follow you in a straight line.
• If they're not chasing you directly you can try burning on a course parallel to theirs and in the same direction, which should also reduce angular velocity.
• If they're trying to keep beyond a particular range (web range, for example) from you, you can try burning straight towards them -- they may make the mistake of burning directly away from you along the course you're travelling.
• If you're fighting a player who's trying to keep outside of web range, but has to stay within the range of a long point to keep you tackled, you can try burning away to get them to chase you, and then turning around and burning towards them -- at least this will disrupt their orbit, and at best you will trick them into web range (again, remember that overheating increases web range).

However, if you're in a ship that is very much larger and slower than your target, you're unlikely to be able to win through good manual piloting.

If you have a PvP fleet of large ships that are struggling to hit a swarm of smaller targets you may find it helpful to spread out, and order each ship to target the enemies furthest away from it. Even if your enemies are flying under your guns individually, you can use the low angular velocity provided by greater range to kill the small ships attacking your fleetmates, who can do the same to the small ships attacking you. (By the same token, large ships are most vulnerable to smaller enemies when they're on their own.)

Other Solutions

Sometimes, however, the solutions to this problem aren't directly related to gunnery. In PvE Level 4 mission-running battleship fits usually outsource frigate problems to drones. In PvP larger ships can use drones, large energy neutralizers or the help of smaller support ships to drive small, fast targets off or kill them.

Gunnery Support Skills

Besides the skills which let you use guns themselves (Small Energy Turret, Medium Projectile Turret, Large Hybrid Turret &c &c -- these skills also give you 5% more damage per level with their related turrets) Eve has a panoply of skills which make your guns more effective. These support skills taken together make a big difference to your DPS, range, tracking and so on; anyone serious about using guns should plan to train most of them to at least level IV, and some of them to level V.

• Controlled Bursts: Reduces capacitor needs of hybrids and lasers by 5%/level. Vital, unless you only use projectile turrets -- in which case, it's useless.
• Gunnery: Lets you fire your guns 2% faster per level (and -2% to cycle time is better than +2% to firepower ). Gunnery V is also a prerequisite for T2 gun skills and T2 tracking computers.
• Motion Prediction: 5% faster gun tracking speed per level.
• Rapid Firing: 4% faster firing per level. This is important because -4% to firing cycle is a 5% increase to DPS. (But also a higher cap demand for hybrids and lasers.)
• Sharpshooter: 5% to optimal range per level. Important for everyone, but especially snipers.
• Surgical Strike: Adds 3% to turret damage/level. This is a rank 4 skill, taking longer to train, so focus on other skills first.
• Trajectory Analysis: Requires Gunnery IV. Improves falloff of your guns, 5%/level. Important for everyone, but especially snipers and Minmatar pilots. (And especially especially Minmatar snipers!).
• Weapon Upgrades: 5% less CPU required to fit turrets and launchers per level. Vital fitting skill.
• Advanced Weapon Upgrades: Requires Weapon Upgrades V. Decreases turret and launcher powergrid requirements by 2%/level. Also a vital fitting skill.

Skills which, while not filed under Gunnery on the character sheet, are particularly significant include:

• The other fitting skills besides Weapon Upgrades and Advanced Weapon Upgrades.
• Capacitor skills -- Energy Systems Operation (faster cap regeneration) and Management (more cap) -- important for everyone, vital for hybrid users and ultra-ultra-ultra vital (!) for laser users.
• Targeting skills. Sig Analysis lets you lock the enemy faster and is important for any combat pilot. Targeting lets you queue more targets. Long Range Targeting lets you target at longer ranges.

See Also

• A very neat, if somewhat old, flash-based guide to gunnery which lets you play around with different signature resolutions, tracking speeds, ranges &c.
• Turret Damage for the mathematics of gunnery. You can also try the information on CCP's own wiki.