My Only Teacher is Nature - Fighter Techniques (OSR/GLOG Compatible)

I rarely ever play fighters. Hybrids, sure. Gishes, paladins, monks, even barbarians, but seldom a farmboy with a sword and board and a yen for adventure. I've always just felt like I was missing out on half the system to play a character without any access to the kind of lateral advancement that spellcasters have. Part of this also stems from a conversation on the GLOG book club, specifically Spwack's idea that fighters need more options to do borderline 'impossible' things, because by standard OSR design philosophy anyone can attempt to do anything possible. There's a lot of wisdom in the old standby of letting fighters try this kind of thing just with a penalty to their attack roll, but I want a way of codifying it into something that feels like an actual way of improving your character. Wizards get the fun of collecting and crafting spells, I want that for fighter-types too. To whit, I have come up with the following rules that I am going to implement in my home OSE and GLOG games; 

Fighters can attempt to perform special techniques; they can try to pull off anything even vaguely plausible, even borderline impossible anime-tier stuff, using any resources available to them. If it's something you'd need a Feat to do in some editions or 10-year-old you believed people could do if only their kung-fu was good enough, a fighter can try it and have a reasonable chance of success. Furthermore, they can refine these attempts into polished techniques they can perform reliably.

This kinda stuff.

Fighters are not just simple warriors after all, they can endure enough damage to kill a normal man several times over, the mightiest of them can take blows from giants that by all rights should reduce them to a pulp. They are proficient with all weapons, a trait that on it's own was sufficient to elevate two members of the Suicide Squad to superhero level. Fighters are instinctual users of the same power that a wizard uses to turn invisible or rend a horde of goblins apart with killing incandescences. 

Here's how you do it;

1. A Fighter can attempt 1 technqiue per day per level, demi-fighters like barbarians and rangers etc. can attempt 1 technique per day for every second level they have. A technique is always attempted as part of an attack roll, and must be declared before the attack.
2. When they first attempt a new technique, the GM should assign it a difficulty out of 1-6. Base difficulty is a 5:6 chance of success, for each additional action's worth of stuff* a technique contains lower this by 1, for each really outlandish action reduce it by 2 or more.
3. Truly extraordinary techniques may have a 0:6 chance of success. However, if they wish, the player may negotiate drawbacks to the technique to reduce the difficulty. Taking a fatigue level, losing a die or two's worth of hp, losing the use of a limb for a certain period, or expending a hard-to-procure resource like a potion are all good examples.
4. If they roll under the success chance on a d6, they do the thing! They should also write down the technique and give it a name, so they can retry the same technique again.
5. If it fails, they should still write it down anyway, except the next time they retry it the difficulty is lowered by 1 point. Every failed attempt in real combat (not sparring) lowers this difficulty. When a technique's success chance is reduced to 6:6 it is now perfected. A perfected technique can be pulled off automatically with a successful attack roll and an expendiature of a daily technique usage. It can even be used after the attack roll is declared successful or not.
6. A character can have a number of techniques in their memory equal to their level. They can still learn new techniques once this limit is filled, but must forget one of their currently memorised techniques to make space. True masters write their perfected techniques into Manuals to avoid losing them permanently (see below).

*To illustrate: a lot of games have rules for sundering, disarming, tripping, grappling, etc. which all take up an attack action, with a technique you can do multiple of those things at once. Like disarming a person with a flick of your blade, grabbing their weapon out of the air, and hitting them with it all in one smooth move (base success chance 2:6).

Special techniques can include any resources at the user's disposal, but if it's tied to a specific weapon's magical effect the user needs that weapon to use the technique, or one with a similar enchantment. An example might be taking a swig of moonshine and spitting it through a flametongue sword. You're going to need at least some flammable liquid and a source of fire to do that.

Why yes, this is all an excuse to post Ranking of Kings gifs, thank you for noticing.

Training & Technique Manuals
A fighter during downtime can spend cash to improve their success chance with a technique, up to a maximum of 5:6 - only testing in the unpredictable nature of real life-and-death combat can perfect a technique. Everyone has a plan until they get punched in the mouth.

Such improvements require access to a training facility with dummy targets, wooden training weapons, and master tutors where the technique can be refined in a semi-scientific fashion. A "fighter's guild", knightly order, mercenary company or the like will likely have such a setup. Training costs a week of effort and 100gp x the chance:6 advanced into. E.g. advancing a technique from a 3:6 to 4:6 costs 400gp.

A technique that has been perfected can also be written into a Manual, which can be read by others to learn the technique. Such Manuals are highly valuable and sought-after, and become a new item of treasure akin to scrolls for wizards. With a Manual a character can freely commit the perfected technique it contains to their memory with only an evening's study.

End Him Rightly

Writing a Manual doesn't require magical ink and uncanny parchment like a scroll, but it does require illustrations. An artist must be employed unless the author is also proficient. It takes a month to write, 500gp, and a successful skill check both for the artist and the author. A failed check results in a flawed manual, with either obtuse language or hard to follow illustrations, reducing the base success chance for the technique learned from it by 1 for each failed roll. The author can of course retry, providing they have enough money and time remaining, and the technique still in their memory.

Example Techniques

Dance of Wrath
Three strikes executed in the time it takes a common man to make one against the closest 3 possible targets within 30ft of each other, friend-or-foe. This technique is so strenuous it costs the user a level of Fatigue.
(Three attacks in one (-3), uncanny movement speed (-2), Doesn't discriminate targets (+1), Fatigue gain (+1), base success chance 2:6)

Fightan.

Don Schiavona's Percipient Defence (I provided this one, but this whole post is mineable.)
Expend a technique use for the day as a reaction to be able to parry even attacks that you are not consciously aware of for the round, allowing you to keep your full Defence and make an opposed attack roll against the first attack made against you this round, negating it if you exceed the attacker's roll. This technique, once perfected, can be used even when unconscious.

(Uncanny defence (-2), one special action (-2), base success chance 1:6)

Shirasampe
A deceptive technique that appears to the untrained (non-Fighters) to be a seemingly supernatural ability to paralyse foes with a blast of chi from the user's palm. In actuality, it employs no magic, merely knowledge of the prana-bindu meridian system and a pebble hurled with supreme speed and accuracy. The victim must Save vs. Breath Weapons or be paralyzed for d6 rounds, or until they take damage.
(Near-magical effect (-3), requires proficiency in medicine (+1), base success chance 3:6)