Kill-based experience

[yrizoud]

(This is a source modification, not a ruleset-based mod)
Latest release : 11/11/2014

I've made an experiment for a different system of soldier experience : The stats would be directly affected by the unit's kill count. Basically, the kill count acts as a "Level".
The main goal is to give me an enticement to play ironman mode, by providing more efficient troops to replace the heavy casualties.
A secondary goal is to remove the weird tactics for raising units' experience (quick bullet weapons for accuracy, firing squads on helpless aliens for reactions)

I chose an experience formula that provides hefty gains initially, but by 3-5 kills, the unit is a veteran who improves slower, 2% or less per kill. Also, unskilled soldiers grow quicker to catch up : by 10 kills, a lousy shot raises from accuracy 40 to 78 (+38), while an ace will have increased from 70 to 92 (+22)

About stunned aliens, I first wanted to attribute a kill to the stunner on mission end, but it involved saving more data in save games. I resolved a simpler system that seems to work well : each capture awards an extra kill to one of your surviving soldiers at random.

I added a tiny bonus for rookies who survive battles but don't manage to get a kill. It's enough to see them improve a little, but it's quickly capped and disappears on the "real" level-up anyway.

So far I'm pretty glad with it. I'm in my 4th month of gameplay, having heavy armors and raided my first alien base (no commander capture though), which cost me 3 dead and 2 wounded. I hired 40 soldiers total, 16 are in the memorial and all the others are somewhat experienced (1-7 kills)

I attach here the compiled exe on Windows, in case somebody wants to see for himself. Requires the files from the same build :
https://openxcom.org/git_builds/openxcom_git_master_2014_04_17_2135.zip

Edit: Here's a chart with the gain formulas. It's supposed to be randomized, but I think the link will only show the last soldier I generated with it.
https://docs.google.com/spreadsheets/d/10RtfLG4JFXqXqvv3oUugGJdKUAD9yfa0KxbAyo1uhRo/edit?usp=sharing

[civilian]

Awesome, I wish this would be an option for the default game! I always use a tiny 8-men squad only during the whole game and rarely see ANY promotions after the initial missions, your idea is WAY better than the hire250soldierstogetacommander approach of the default game.

[Solarius Scorch]

While I prefer the original approach - promotions for brave deeds is rarely good idea - I understand your reasoning regarding Iron Man games. Just please, don't make it the default option

[Shoes]

You can take a look at my stat tracking mod for how I track kills. Or you can copy/paste the relevant code and do what you want with it ;p Gain more xp for killing an floater engineer in the dark, why not!

[yrizoud]

I wish this would be an option for the default game!

You may want to test it once, first Maybe by the end of a game, you'll already feel bored with it.
Balancing is extremely subjective, too.
I still haven't touched psi skill, but I think I'll make it progress only in psi lab (grinding psi is just dull, and gain-more-when-success is completely backwards).

Shoes: I will look at your branch if I see I need to track more data, but in the scope of this test, I doubt it :
I specifically wanted something which doesn't entice the player try awkard things on purpose, because it rewards more the loopholes than the normal gameplay.
And I wanted to avoid "double rewards" : If an unlikely shot connects, you have already been rewarded because this threat is gone and you have more time this turn, which makes it more likely everybody goes home alive. No need for a second reward (stats), which makes it more likely this soldier gets more kills, which gives him more stats (triple reward!).

[yrizoud]

Updated with latest OpenXcom (27 october 2014)
- Soldier stats are now (re-)assigned when you load a saved game. This means you can test the mod by loading one of your existing saved games. It also helps updating soldier stats, in case future versions change the formulas.

[new_civilian]

As much as I like it: I will not use it because I would miss out on all the additional features another EXE gives me. Seriously, guys: Please start to cooperate on things like that! Imagine the Realvision, Extended, Commendations and now this exe COMBINED into one: ---- Can you say X-Com heaven? 

Or talk to Warboy, maybe he can add those features to the game. Right now most of these changes, as desirable as they are, are simply wasted.

[TaxxiDriver]

As much as I like it: I will not use it because I would miss out on all the additional features another EXE gives me. Seriously, guys: Please start to cooperate on things like that! Imagine the Realvision, Extended, Commendations and now this exe COMBINED into one: ---- Can you say X-Com heaven? 

This. I also hope those mods could be compatible, maybe even be included in the official version as an option! That would be... pure awesome.

[Edited] Changed the sentences and added some since the meaning was somewhat vague. Sorry for that.

[yrizoud]

It's pretty difficult to find goals that everybody agrees on. In this case, I'm not even completely convinced my own idea is good (A training facility system may be much more balanced)

[CryptoCactus]

Realvision

Yeah, if that was included by default, those of us running the game on potatoes would be kill.

[Arthanor]

Having vision range defined as a number (default = 20), with night vision range being 0.45 of the day number for XCom (so default = 9) would work beautifully. People with fast computers could crank it up and we could keep it low.

There are ways to make things coexist, but making so many options is tricky. Hopefully the simpler changes will be integrated once TftD is done (especially those that are either on or off, like this one).

[CryptoCactus]

True true. I suppose we could always do with more "Advanced Options" for stuff like this

[LeBashar]

yrizoud, your system have some flaw for me : if the experience is gain only with kill, some soldiers will gain far faster than another which never gain anything. For example, the sniper will gain experience quiclky, but the machinegunner probably not, and scouts never. This discourage the specialisation, no ?

[yrizoud]

In my tests (with FMP and range-based accuracy) I didn't see unfair gains depending on roles. Playing with no save game, trying to get everybody home alive, but still trying to get every rookie his first kill.
I agree however that it involves a lot of "staff rotations", because the first kills change a lot of things : A weak grenadier who kicks ass in one mission can have enough gains to become a reliable heavy weapon specialist in the next mission(s).
I'm pretty sure it calms down when the team stabilizes, as the more kills, the less difference it makes.

I agree that with the way I put well-rounded growths, soldiers with similar kill counts tend to resemble each other a lot. Maybe I could set different growth profiles, either selected by player using a keyword in name, or hidden (the player discovers the growth).
The first system may be more rich, but I'm afraid it's the hardest to balance and easiest to abuse ("I need sharpshooters and nothing else")