Experience

A soldier earns experience during combat. After the mission, the soldier will then earn a random amount of stat increases based on what experience the soldier acquired during combat.

How Experience Points Are Applied

Soldier stats can be divided into two areas, primary and secondary stats.

Primary Stats

• Primary stats only increase when particular actions are performed. To see exactly how to trigger each stat, follow its link. The stats are:
  • Psi Skill
  • Firing Accuracy
  • Reactions
  • Throwing Accuracy
  • Melee Accuracy

• The number of primary skill points you earn at the end of a combat mission relies solely on the number of primary actions you perform during combat. Your current skill level doesn't matter. It doesn't matter if you have the lowest recruit value, or you're one point below the cap.

• Points assigned have a stairstep function, corresponding to a range within which points are rolled. The range increases as more actions are performed:

  Primary   Roll   Average
  Actions*  Range  Increase     *Successful Psi actions count as 3 actions - see below
    1-2      0-1     0.5
    3-5      1-3     2.0
    6-10     1-4     2.5
    11+      2-6     4.0

• Performing more than 11 actions doesn't cause any more increase. This was tested out to 200 actions. Once you reach 11, you get a 2-6 roll, and that's that.

• As you can see, there are distinct breakpoints at 3 actions and 11 actions, corresponding to an average increase of 2 and 4 skill points, respectively. Three actions are the best "bang for the buck", if you have a limited number to spread across your squad (a.k.a., a limited number of aliens to kill). It's not an issue with psi or throwing (which you can do all you want), but is for other primaries. Then again, letting your soldiers throw 3 times just before ending a mission maximizes Throwing Accuracy growth vs. your personal time spent. That is, if you give a damn about Throwing.

• A 0 roll is not possible for primary skills, if you perform 3 or more actions. See ranges (above). Conversely, one or two actions do not guarantee a skill increase, and your second action can even be seen as a waste, because it soaks up an action without increasing the roll range. If someone's done one or two actions, try to get them to three, if you can.

• Psi actions are a special case. Successful panic or mind control (MC) attempts cause the psi experience counter to go up by three actions. Thus, you only need to do 4 successful MCs or panics to get all the psi skill points you're going to (4x3=an experience count of 12). But unsuccessful attempts only cause the counter to go up by one. So you need 11 failed attempts to get to the 2-6 roll range, just like for all other primary stats.

• When you think about it, Ye Olde Programmers Of Yore made a simple and robust system where all squaddies are expected to participate, and hopefully each of them get to make a few primary actions that increase their score some real amount each combat mission. (And only fools test out to 200 actions - Ed.)

• It is possible to get +6 skill points if you did 11+ actions when at Cap -1, which means that an 'overflow' maximum stat value (on last mission before going over cap) of Cap+5 (but no more) is possible. See Regarding Caps. Few of your soldiers will ever achieve Cap+5, however. First, you have to catch the fact that one of your soldiers is right at Cap-1 and be sure to do 11+ actions next combat. Then, there's only a 20% chance of rolling a 6 (with range 2-6). Finally, you do have to be right at Cap-1, without having overflowed to some lower Cap+ value previously. So probably only a few percent of soldiers will ever see Cap+5 - except for Psi Skill, which has no true cap. (And Psi skill is probably the only primary stat you'll get to cap anyway, unless you're into real marathon games!)

Secondary Stats

• Secondary stats increase when one or more primary actions are performed (except for throwing). Secondary skills are:
  • TUs
  • Energy/Stamina
  • Health
  • Strength

• Secondary skill points work the exact opposite way of primary skills: It does not matter how many primary actions are taken; all that matters is that you did one primary action - and your secondaries increase all that they're gonna. It also doesn't matter if you did more than one kind of primary skill.

• Also opposite to primaries, current stat level does matter for secondaries. An easy way to visualize it is that, if secondary stat levels were at 0 (via hacking), you'd get an average of 4 points (range 0-8) per combat. This slopes evenly down to getting an average of 1 point (range 0-2) per combat at the cap for each stat. This is actually a charitable simplification; for the gory details, see this.

• Viewed as an even slope, Stamina has the "farthest to go" to max out. A table can be composed of how many combats are needed to max out each secondary stat, on average:

                TIME UNITS       STAMINA (ENERGY)        STRENGTH             HEALTH
            Level  Inc.  CMs     Level  Inc.  CMs    Level  Inc.  CMs    Level  Inc.  CMs
  R_Min       50   2.20            40   4.00           20   6.00           25   3.80    
  R_Max       60   1.67    6       70   1.86   12      40   2.50    6      40   2.00    6
  Cap         80   1.00   15      100   1.00   22      70   1.00   19      60   1.00   14
  Total                   21                   34                  25                  20

• This table shows Recruit Min and Max levels, and the Cap for each stat. Then it shows the average Increase per combat mission at each of these three levels. For example, you get +2.20 TU skill point increase per combat, on average, when at TUs=50. Then "CMs" shows the number of Combat Missions to go from e.g. TU Recruit Min to Recruit Max (takes 6 CMs), on the average, where you are successively adding a little less points each CM. The next CMs entry is number of combats to go from Recruit Max to Cap. Finally, "Total" shows the total average CMs to go from Recruit Min to Cap. Of course, the actual number of points assigned is highly variable (it's rolled randomly within the range of points possible), so you may get real lucky (or unlucky) in any one stat. These are only averages.

• As stated, Stamina has the "farthest to go" (34 turns in total from Recruit Minimum to Cap). So if you're aiming to have soldiers that hit their caps across the board a.s.a.p., favor a high recruit Stamina over other secondary stats.

• Note that even if a primary skill is over its cap, you can still increase (non-capped) secondaries by performing a capped primary action.

• As stated, all secondaries have "slowed" to getting only 0-2 points when at Cap-1. Thus, you can only have an 'overflow' (on last combat mission when you go over the cap value) of Cap+1 for secondaries. Considering the probabilities involved, soldiers have a 25% chance of getting Cap+1.

Exceptions

• Bravery is unlike other skills. +10 Bravery may be awarded if a soldier loses control due to heavy morale loss (loss of comrades or psi panic attacks). Each time a soldier panics or goes berzerk, they have a 10% chance of gaining +10 Bravery at the end of the mission. If a soldier berzerks/panics 11+ times in a mission, the Bravery gain is guaranteed. A soldier can only gain 10 Bravery per mission, and Bravery maxes out at 100.

• It can be trained easily and safely once you have completely secured a mission field. Capture (i.e, Mind Control) one or more psi-enabled aliens (Ethereals or Sectoid Leaders/Commanders) and box them into a corner (or the Avenger) so you can shoot them later. Fully disarm the aliens using the [trick], and have all your soldiers drop all their weapons and grenades as well so they don't kill each other.

• Now you can hit the End Turn button repeatedly while the aliens go to work on your psi-weaklings. Soldiers with a Psi Strength of 80+ seem to be immune to psi attacks (use them to wall the aliens in), but all others can be trained. Move any soldiers that have panicked or berzerked repeatedly as far away from the aliens as possible to give less psi-weak soldiers a chance to get trained. Aliens favor attacking psi-weak soldiers, but also nearby soldiers. They also cannot mind-control soldiers past a certain distance, so move your weakest soldiers to a distance where they can only be panicked, not controlled. You may need to mind-control the aliens periodically in order to regain control of your troops so as to move them away.

For additional info, see Bravery.

• Throwing is also an oddball. While it follows the rules for primaries (above), it only increases your Throwing Accuracy. It does not trigger secondaries to increase. (It would've been too easy to increase stats, otherwise! Actually, Psi is even easier, but at least it takes a while to research psi.)

Putting It All Together

• Your brain probably focused on the averages stated above, but the actual points assigned are entirely random. The range is the correct indicator of what to expect for any one soldier on any one combat mission. This follows the usual XCOM approach of defining a range and rolling randomly within it.

• Do your best to get every soldier you are interested in developing, to get at least one primary action (not including throwing). This makes sure their secondaries grow. Then try to shoot for the big breakpoints of 3 or 11 primary actions. Doing more than 11 actions does not increase a particular primary stat any more, so spread the actions around if somebody has already done that many.

• Any soldier can (and will!) ultimately become a maxed-out superman. The worse a secondary stat is, the quicker it will rise. And you can try to target who performs which primary actions. Along these lines, knowing the breakpoints of 3 and 11 can help you manage potential skill increases (a.k.a. targets) as effectively as possible. That said,

• Early in the game, don't spend much time or money fretting over stats. Any soldier is liable to come up snakes with their Psi strength. And every soldier can otherwise eventually become a superman.

• As many sages have said, one of the best ways to max experience - once you have psi on board - is to 1) mind control aliens, 2) line them up for a firing squad, 3) put a couple of laser pistols in their hands (once everybody has powered or flying armor), then 4) reaction fire with standard-issue pistols. This increases your psi, firing, reaction, and secondary skills. For more tips on increasing skills, see the links at the bottom of the Firing Accuracy page.

• The truly devious might want to keep a pet Muton base (once you have psi ability). Drop in, kill them down to one Mutie, and withdraw. Milk those thick-skinned greenies til you're maxxed! - Tip from Zombie

• In the endgame (when you have tons of cash), if you're a micromanager role-playing to make soldiers who are maxxed across the board, it's arguably more important to pick recruits who are not anomalousy low in any one stat, rather than ones who are high in a few things. In other words, if your goal is 100% stats, one really bad stat may slow you down more than e.g. being a particularly good newbie shooter. Firing accuracy, reactions, and stamina have the biggest span between recruit values and work needed to max them out. Related to this: Reactions are easier to increase with firing squads than Firing Accuracy (reaction shots count even if they miss, but only hits count for Firing Accuracy; however, a Reaction level of below 50 or especially 40 can be crippling, because everybody else will fire first and kill the targets). Anomalously low stats can also be the basis for throwing out soldiers who "aren't performing" - if one of their stats is much farther from the maximum than the rest.

Another thing to keep in mind is that rank is only window dressing. The only thing it affects in the game, is his or her "soldier value" - the score (victory point) loss and morale hit to your other soldiers, if that soldier dies. Rank doesn't otherwise cause your stats to increase faster, shots to hit better, or affect anything else.

Regarding Caps

Every soldier statistic has a maximum allowed value, as shown in the table below. Your soldier will eventually have a value equal to or slightly greater than the cap. It is allowed to go over the cap, the very last time you have a combat while it is still under the cap. For example, the maximum Firing Accuracy is 120. If you go into a combat at 119, do lots of shooting, and get a +5 roll, you will walk away with 124 Firing Accuracy - but it will never increase again. (Unless you like to hack... heh heh heh.)

Primary skills can overflow their cap by 5, and secondary skills can overflow their cap by 1, as shown here:

Primary Stat         Min Cap     Max Cap
Psi Skill              100         105+*
Firing Accuracy        120         125
Reactions              100         105
Throwing Accuracy      120         125
Melee Accuracy         120         125

Secondary Stat       Min Cap     Max Cap
Time Units              80          81
Stamina                100         101
Health                  60          61
Strength                70          71

*Psi Skill is the only exception to the cap rule. Combat will operate normally - you'll never see an increase from combat once you're 100+ Psi Skill - but Psi Lab training will continue to add 1-3 points each month.

FWIW: You have a 25% chance of getting Cap+1 for secondary skills, and you have no control over what happens (barring reloading your game and ending combat again).

For primaries, a soldier that does 11+ actions (for a 2-6 roll) every single combat mission will get Cap+5 in that primary skill 5% of the time, on average. By "every single mission" I mean, without regard for the fact you're nearing the cap (and playing with the possible roll results). You can increase the odds to as high as 20%, if you use the primary increase roll ranges to inch your way up to Cap-1, then do 11+ actions on your final combat. Or you can have a 0% chance of Cap+5 if you don't pay attention and don't do 11+ actions near the cap!

Misc Notes

• With the exception of Psi Skill training in the Psi Lab, all stats can only be trained through combat experience.

• Any combat experience earned will influence promotions. The soldier with the highest amount of experience in total will have the best chance of being promoted to the next rank. Yes, panicking counts towards a promotion as well.
  

See Also

• For more information on individual soldier stats, see Soldiers
• For info on "training" for experience, see Experience Training
• For "behind the scenes" on experience testing (a.k.a. how testing was done in nauseating detail), see here