User talk:MikeTheRed

Here be more detail than you ever wanted to know. Please put comments/question in italics. If you want an email reply, either be a regular of here or xcomufo.com, make a User page, or just type in yer email addy.

The Experience of Experience

A.K.A. more details than you ever wanted to know, about testing XCOM:UD 1.4 experience counters versus stat increases

My observations under Experience are getting incredibly long-winded. And at the same time, I am doing yet more research on it. So I've made this space to put levels of detail that are way more than a casual player is interested in. I will probably move some stuff out of Experience and over to here as I polish the info.

Non-Randomness

This section only applies to primary skill increases:

When I've talked about experience rolls, I've made it sound like you always get the average (halfway between the ranges). But this is definitely not the case, especially when there are very few experience points (EPs) in UNITREF offsets 80-85. Specifically, when there are only 1 or 2 primary actions - the first 'step' for primary skill points - I saw very weird, non-random stuff. Example: I would set up 16 soldiers, with only 1 or 2 EPs for each soldier. When I ended the combat, the skill point range was undeniably 0-1. But far more often than not, the 16 soldiers in my test crew would all get 0 skill points, all across the board. Then every now and then they would all get 1 skill point, all across the board. And even less often, there would be a mix of 0s and 1s in the results. The actual average increase was about 0.2 points, not the 0.5 points I wrote in Experience. To this day, I cannot get a handle on what is triggering them to all be 0 or 1. My best guess is that it is based on some high-level bit mask over the system clock... it seems to come and go in unpredictable spurts. (If this is true, it's possible that my DosBox wrapper is messing with the results. But then, it would be for anyone using DosBox.) I did my testing by reloading and combat-ending approx. 20 different hacked combat-mission savegames (as I zeroed in on issues to test) hundreds of times in sum total, so I can never be sure my problems weren't caused by the simple fact that I was reloading a few games many times, instead of racking up experience points au natural, where some unknown randomness seed might be being kept somewhere.

Anyway, I kept the main wiki summary simple, and just strongly advised people to try to get at least three primary actions. Although 1-2 actions was weird, by 3 actions I saw little non-randomness. More precisely, I saw some non-randomness, such as all stats getting the exact same result for several tests in a row. But, when summarized across any larger n (20+ tests), the summary stats were always close to the average of the range. So, there was a little bit of weirdness at 3+ actions... but it was nothing like at 1-2 actions.

Secondary "Steps"

In the wiki on secondary stats, I said that there is an even slope for secondary skill point gains, from an average of 4 (range 0-8) at (hacked) secondary level 0, to an average of 1 (range 0-2) at Cap-1. That was a simplification, to keep the wiki short. In actuality, it's like this:

The three stats TUs, Health, and Strength have a maximum range that increases by 1 at every increment of 10, working backward from the cap. Stamina - that high-winded beast - increases at multiples of 15. This follows the usual X-COM approach of defining a range and rolling randomly within it. So a graph of the maximum range of points possible vs. current stat level looks like this:

Thus e.g. TUs has a range max of 2 from stat level 71-79 (80 is the cap), 3 from 61-70, 4 from 51-60, etc. TUs, Health, and Strength work backward in increments of 10, but Stamina has steps 15 stat points wide. So it has a range max of 2 from stat level level 86-99, 3 from 71-85, etc.

(All secondary skills have a range minimum of 0 across their span; it's entirely possible to not get an increase in a secondary skill after a combat. So on average, you expect to get half the range maximum.)

Interestingly, at (hacked) stat level=0, Stamina and Health can get 8 points assigned (like I said in the wiki), but Strength can get 9 points, and TUs can get 10. Then all of them quickly drop the range to 1 point less, at level=1 (except Stamina, working backwards in steps of 15).

So this step function means that the "even slope" I talked about is not quite correct, nor are the averages that I put in that table for each level (those are based on a linear slope equation instead of half of that step's range maximum, which is what the true case is). Still, it's a very good simplification, especially when you're talking about the average number of CMs to go from e.g. Recruit Max to Cap. So I kept the wiki shorter by not going into the level of detail shown here.