Fighter: Student of Many Styles

It's a fighter that develops in random directions, steered by the player.
This is not polished, it is minimum viable product. Only the barest thoughts have been given to balance. This might be overtuned. On the other hand, fighters should be good at fighting.
I think that you could take Parry, good with shields, the parry-improving technique, and wear heavy armour and you'll be REALLY hard to kill. I'm not sure how I feel about that.

Or if you got extra reach, cleave, and finished with Kill The Mooks you'd be able to mow down weaklings like anything.

I can see some anti-synergies between some things: if you punish misses by attacking more, and attach a maneuver to each of your attacks, so the enemy tries to hit you and misses EVEN MORE,for more attacks... then is it good or bad for you to improve your maneuver so that it doesn't provoke enemy attacks? Same thing with a crit build vs Kill The Mooks.

I also note that it's quite possible to create a fighter that only ever gets one attack per round. That sorta feels wrong. But maybe that's OK.

 In short: if something in this feels wrong for you, it probably is wrong, and should be adjusted.

Chassis

A: 2 Fundamentals, 1 Technique, Attack +1
B: 1 Technique, Attack +1, Extra skill
C: 1 Fundamental, 1 Technique, Students
D: 1 Secret Art, 1 Swappable Technique

You begin with an interesting scar, two weapons OR a weapon and shield, medium armour, and a tome of esoteric fighting techniques.
You are proficient with all normal weapons and armour.
Starting Skill: 1. Mercenary 2. Foreign Parts 3. Monsters

Fundamentals

Each time you get a Fundamental, pick an item on this list.

• Weapon Notches: Weapons get better at 3, 10, 30, and 100 kills. You can take the same thing more than once.
  
• +1 attack
• +1 damage
• Extra thing
• Keen edge
• Parry: Or you can call it Stance. You have [2, 3, 4, 5] hp of overshields each round.
• Tactic master: When you hit an enemy, you can also make a maneuver against them (does not remove the normal chance of being hit)
  
• Cleave: When you kill an enemy or crit, you can make an extra attack.
• Good with Shields: Extra +1 Armour from shields, can always sunder for maximum
• The Good Power Attack: When you power attack, the penalty is only -2 rather than -4.
  

Technique

Each time you get a new Technique, roll TWICE on the list, and pick ONE to gain. If you get an entry you already have, reroll that one. I kinda want to be able to increase this chart to a D66, so I need 3 more ideas.

1. Head of John: Your head becomes indestructible. It's a good weapon.
2. Pattram Sword Hand: Your unarmed strikes are just like swords. Work out the specifics.
3. Horse Stance: You no longer get tired from walking or running any distance as long as you are not overencumbered.
4. Chan Style: No item you use as a weapon does less than 1d8 hp and you don't take penalties just for trying to use it (though it may only be good for one use if fragile). If you have a strength penalty to attack/damage, that's also ignored.
5. Swat Missiles: You can smack incoming missiles out of the air if you make a successful attack roll.
6. Protecc but also Attacc: If an ally is attacked by an enemy, both within your reach, you may make an attack against that enemy first.
7. First strike: When an enemy moves within your reach, you may make an attack against them immediately.
8. Infinite Tumble: Move past enemies or disengage without provoking attacks
9. Discliple of Guts: You learn how to carry and effectively use ridiculously oversized weaponry.
10. Punish Incompetence: When an enemy misses you, you may make an attack against them.
11. Keen. Your critical range expands by one.
12. Spellsword: Roll a random spell and gain one MD. You're good with spells now.
13. Bloodlust: Gain HP when you kill an enemy, equal to how many HD they had. No "angry turtles in a bag" strategy, please.
14. Ignore Injury: Mere pain, shock, bruising, bleeding, cold, burns and the like no longer hampers your ability to act - only extensive damage like shattered bones or loss of limb.
15. Follow Through: When you kill a creature, damage exceeding their remaining hitpoints gets applied to other targets you could also conceivably attack with the same action.
16. Size up: Can tell most important enemy stats at a glance: hitpoints, armour, and their strategy.
17. Air Blade: Can make ranged attacks with melee weapons.
18. Implacable: You are immune to fear and get a +4 to saves against other mental effects. Allies near you get a +4 to saves against fear.
19. Extreme Parry: Double your parry.
20. Dash Master: Get a 10' Dash as the Skirmisher (that is, a 10' horizontal dash, 1/round, usable at any time including when an enemy is about to attack you)
    
21. Extra Quickdraw Slots: You get another 3, like a Thief
22. Lightfoot: Your footsteps are so light you can tread on water or snow without falling. +2 stealth.
23. Elemental Affinity: Pick an element. You can use it to perform 1d6 attacks and achieve other small-scale effects.
    
24. Elemental Resistance: Pick an element. You gain resistance to that element equal to your HD.
25. Danger Sense: You cannot be surprised.
    
26. Situational Extra Attack: Come up with some particular circumstance that gives you an extra attack.
    
27. Effective medicine: Gain the Medicine skill. Rolls to prevent someone dying from their injuries succeed on a 3 in 6.
28. Equipment trick: You can make better use of a kind of equipment, especially in combat. E.g. drinking things like potions can be done for free. Or you're good at using ropes are weapons.
29. Zoom Punch: Space seems to warp around you, your reach is much longer than usual.
    
30. Petition DM: Ask for a certain item on the list, or a feature you can find from another class, or something custom, of appropriate power. Try improving a technique you already have, or some set of circumstances that gives you an extra attack?

Other ideas: Extra HP. Reduce impact of Death Dice (make them d4s). Not being able to see doesn't negatively affect your ability to fight.

Attack +1

This is a +1 to your ATTACK ROLLS, not an extra attack.

Extra Skill

Gain an appropriate skill.
[To do: suggest some skills]

Students

A travelling student finds you, wishing to learn from your example. Treat them as a level 1 Student of Many Styles. After a week of learning from you, treat them as a level 2 Student of Many Styles; the technique they gain must be one you have. After a month, they will move on (and are soon replaced by a new student) unless they are furnished with a good reason to stay.
They are willing to EITHER pay you, work for you, or fight for you in exchange for teaching.

Swappable Technique

Pick a technique on the list, gain it immediately. You find this technique difficult; it runs against your deeply ingrained habits, and requires regular practice/meditation for it to remain usable.
You may swap this technique out for another in a week of downtime.

Secret Art

You gain one secret art: some ability of significant power, known to very few.  You might be the only living practicioner. You get a secret art that is most appropriate for your character - according to your needs or historical approach to solving problems. You and your DM can work out the specifics. Some examples are given.

• Ability to cut things that should not be cuttable, such as very hard materials, or space, or truth (pick ONE)
• Perfect Tactical Foresight: declare that the combat round that just happened was only "what you saw might happen". Everything gets put back as it was a round ago and we get a do-over. Nobody will be able to remember the exact hitpoint totals that anything had - close enough is good enough.
• Hadouken. A big one.
• Za Warudo. Two full rounds of action. Once a day.
• Kill the Mooks. Attacks against nameless mooks (2HD or less that the DM hasn't named) always hit and always kill.

Thieves' Guild: Greaser

This is a Thief Guild following the format invented by Velexiraptor, as follows:

Level 1: Gain 2 abilities at rank 1
Level 2: Rank up an ability you have, then gain a new ability at rank 1
Level 3: Rank up 2 abilities you have
Level 4: Rank up 2 abilities you have, then gain all abilities you don't have yet at rank 1

Hit Die: d6 (if you use those)

If you use weapon proficiencies, you are proficient with greaser weapons - that is, practical urbanite stuff.

 Starting Equipment: Comb, Jumbo tub of thick grease, hand mirror, spring-loaded knife, stylish outfit, a narrative-and-setting-appropriate mode of transportation (horse, motorbike, T-Bird) that only performs properly for you.

Skills (2, d6): 1. Dance, 2. Smooth-talk, 3. Vehicle/driving/riding skill appropriate to your original mode of transportation, 4. Streetwise, 5. Gambler, 6. Bravado

1. Dance-Fighting

    ✧: You may dance-fight. You must not be encumbered or have anything else hampering your movement, and be able to hear some kind of appropriate and familiar music to quicken your soul. A group of people clicking fingers in unison works in a pinch, as does hallucinatory music. You get +2 to your AC and Attack against foes that cannot match your smooth moves.

    ✧✧: You may add your dex bonus to damage rolls (instead of strength) while dance-fighting. If you are hampered or the music stops while you are dance-fighting, you retain the benefits for two more rounds.

    ✧✧✧: You can lead a small group of people to dance-fight, though they are subject to the same restrictions and must be able to see and hear you. You can always hear your theme song if you concentrate.

2. Home Turf

    ✧: Declare a Home Turf no larger than a small town. You always know the fastest route through your Home Turf and can always find a place to lay low there.

    ✧✧: Once per week you can declare you Know A Guy from your Home Turf who could conceivably assist with the current situation. The GM rolls that person's Reaction when they are next encountered - they may require appeasement or refuse entirely.

    ✧✧✧: Gain a Reputation in your Home Turf as befits what is known of your actions. Everyone has heard of you (though you are not always recognised on sight). Discuss with your GM what this reputation is and what effects it will have. This reputation can be changed over time through great effort.

3. Percussive Maintenance

    ✧: Precisely strike an object that is entirely mechanical and entirely comprehensible to you, with a body part, after studying it for at least one round; this makes it immediately perform as you would like, within the realms of physical possibility. You can ignore one of these underlined clauses but if you do, you only succeed on 2-in-6. You may not retry unless you meet all clauses.

    ✧✧: You can now ignore two underlined clauses, but if you do your success rate is only 1-in-6. If you fail, you may retry once without having to meet all clauses.

    ✧✧✧: Ignoring one clause succeeds on 5-in-6. Ignoring two succeeds on 3-in-6.

4. Fast Hands

    ✧: You can draw and make use of the item in your very first inventory slot even if surprised.

    ✧✧: Gain an extra two quick draw slots. Get the ✧ benefit for your second inventory slot also.

    ✧✧✧: You can declare that an item in a quickdraw slot is already in your hand, once per hand per round, as long as you could have reached it.

5. Pompadour

    ✧: With 10 minutes of work and the correct tools, you may style your hair beyond the ken of mortal man. Hats/helmets/etc will ruin it. You may sunder your hairstyle to reduce damage from an incoming attack by 1d6, similar to a shield; you gain advantage on attack rolls against whatever ruined your hair until you hit them.

    ✧✧: When you sunder your hairstyle it reduces incoming damage by 1d6+2 points. You gain advantage on the attacker until you have hit them twice.

    ✧✧✧: When you sunder your hairstyle it reduces incoming damage by 1d6+4 points.You roll damage twice and take the higher result the next two times you hit the attacker.

6.  Magnetic Personality

    ✧: When Reactions are rolled you can adjust the result to be one point more favourable if you are prominently visible and groomed properly. (Not all creatures have variable Reactions.)

    ✧✧: While you are in a location where you are regarded well, you can draw a room of people to come to your aid if you succeed on a Charisma check. They are not much more willing to endanger themselves than usual. Misusing this ability may cause people to dislike you.

    ✧✧✧: All else being equal, anyone will take your side of the story.

GLOG Class: Really Mischievous Goose

Explanation: I ran a quick oneshot adventure for some newbies in GLOG (Many Rats on Sticks) with included some pregenerated characters. I made sure to provide some of the classic Wizards and Knights but also the weirder ones such as a Really Good Dog and Really Angry Goose.

It happens that in the time between the original Angry Goose blogpost and the time of my game, Untitled Goose Game had been released and was still very much in everyone's minds which I think was the reason that the pregen Goose got picked for play (and in fact was almost fought over). However, these two geese are actually quite different in methodology and abilities. So, I felt inclined to (mainly as an exercise) write a new Goose class that would be better at the kind of shenanigans that the Untitled Goose Game antagonist gets up to.

And here it is.

Really Mischievous Goose

Starting Items: none, but you have a SERRATED BEAK AND TONGUE, a MAJESTIC WINGSPAN, and a TERRIBLE HONK.

You are a goose.
You cannot climb ropes or ladders. You cannot love.
You cannot speak Common. You speak Goose fluently. You can understand the approximate meaning of other PCs and anyone they are talking to.
You have a prehensile neck and your head can fit into tiny spaces. You can fly if you have enough space. You can float on water.
You can discern North. Instead of Intelligence, you get Goose Intelligence, which is mainly worse at anything Social or Nerdy.
Your Movement is 8 (Human Movement is 12) but if you have 50' to take off you can fly at Movement 20. Your bite attack deals 1d6+STR damage. Your feathers give you +2 defense as though you had armor, but take up no Inventory slots. You have half as many Inventory Slots as usual.

Starting skill (1d3):
1. Horrible Goose
2. Cunning Goose
3. Asshole Goose

You get +1 Stealth for every Template you have in this class.

A: Fearsome Honk, Clean Appearance
B: Cruel and Unusual, Bad from Beak to Bottom
C: Vicious Grip, In Plain Sight
D: Greedy Goose

Fearsome Honk: All non-ally creatures whose HD does not exceed your level within 20' who hear your Terrible Honk must Save vs Fear or be frightened for one round. If your level exceeds their HD by 2 or more, they continue being frightened until they pass a Save vs Fear (once at the end of each of their turns).

Clean Appearance: You always look neat and clean, no matter what mischief you've been up to.

Cruel and Unusual: If you gain victory over and humiliate an adversary, recover 1HP. You can recover this health only once per adversary each day.

Bad from Beak to Bottom: You gain the Pickpocket skill. If you already have that, instead gain a different criminal skill of your choice.

Vicious Grip: You can now attempt to Grab with every bite attack.

In Plain Sight: As long as a creature has something pressing to attend to, you can try to escape their attention as long as you're not being actively mischievous or threatening at that moment (using normal stealth rules). Loitering or even staring with your soulless, calculating goose eyes doesn't count.

Greedy Goose: If able to calmly collect your thoughts (not suffering from a major status effect or in combat) you may treat your strength and dexterity as being four points higher when attempting to gain possession of a desirable object.