House Rules and Commentary

The Hub & Spokes

Innate Skills

I will use the this terminology from time to time. It's not something that's mentioned in the base game's rules, but the idea comes up frequently enough, and is hard to adjudicate, so I'm just giving it a name and some standard rules: An Innate Skill is given by a trait, and it functions in all respects like said skill, but it open's for free and at the rank of the root Stat(s) at character creation or at the time of receiving the trait. This skill then advances separately from the root stat, and can be improved during character creation with Lifepath skill points. This is easier than trying to remember which skills are innate with which stats, and any difficulties covering the status of FoRKs becomes implicit.

Noticing Things (and Graduated Tests)

There is often some confusion between the use of the Perception stat and the Observation skill. By and large the distinction is as follows: Perception is used to notice things passively with one's senses and mental acuity, while Observation is used to actively look for something (especially things that are deliberately hidden or actively hiding). To aid this distinction note that Observation tests are almost always versus tests, while Perception tests for noticing things are always graduated. Either the GM or player can call for a graduated Perception or a Wises test at any time—usually while dungeon crawling, but really anywhere—to see if the PCs notice or remember anything important when they enter a new room.
A graduated test is explained on BWG pg 26, but are barely ever mentioned again. Most graduated tests count as base Ob 0 (routine), unless there are additional penalties from things like light; but we're really more interested in seeing how many marginal successes you get. The number of successes are then either judged against the GMs private list of information to give out, or compared to the table below for more general information to give out. The wises obstacles and the absolute obstacles list (on pg 15) have been combined here for a good list of success comparisons:

1s	Common knowledge / requires little thought / cursory information	5s	Rare goods / awfully convenient plot detail / requires expertise
2s	Interesting facts / basic information	6s	Bizarre or obscure facts / requires a heroic effort
3s	Details / convenient plot detail / requires concentration	7s	Freaky details / improbable knowledge / a hidden secret
4s	Uncommon knowledge / a simple secret	8s	Forbidden knowledge / requires almost preternatural insight

Personal Note: So far in my games, routine tests have been the hardest type to come by; frequently my players are stuck with B2s that they opened but didn't advanced during character creation for dozens of sessions while their B3s and B4s slowly get to advance up to B5s and B6s. The B2 has gotten a bit of a reputation at my table for this reason, but maybe it's because I haven't given out enough graduated tests? This might also be why I haven't had much fun with wises recently either. The example of a graduated test being used on pg 26 is really quite insightful: in it, it shows that a quick Perception or Wises tests can be used like spot checks in other TTRPGs, intent and task become a little less important to announce before the test, and perhaps this this improves pacing? So I will try this for a while and see how it goes.

Artha

Partly as a way to not make Deeds expenditure feel invalid amongst so many other magic systems (and make no mistake, the Artha cycle is a magic system), partly for thematic reasons, and partly because Call-Ons already half-invalidate the usefulness of Deeds expenditure, I use the following buffs to the artha mechanics:
Saving Grace no longer acts as a mere call-on does. Instead, it will make the test succeed—but you won't get to mark advancement, and there's no marginal successes. Basically, it's for those "I don't care about marking the test, I just wish I had passed that". The Deeds point still contributes towards an epiphany though.
Divine Aura no longer just lasts the scene. It simply removes all your current wounds*. I make this change because I feel that the 5 fate, 3 persona, an 1 deeds getting burned into nothing—not marking anything towards an epiphany—is enough of a sacrifice, and so it's okay to make this effect more powerful. However, there is an asterisk for this effect: a caveat that only immortals and heroes can do this, not the common folk. It also gives a little more permission to the other magic systems to add some extra healing magic effects.
Focus isn't changed, but it is emphasised in my games. Did you even know there's an Artha power called Focus? I sure didn't for the first two years I ran this game! I'm 99% sure that it's there so that you can get an advantage die, and have it contribute to the test difficulty; so you can get more routine tests if you need them. It lets you work Carefully (+1D) and then you can spend a Persona if you fail the test, to nullify the additional failure consequence imposed by working carefully. Basically it's a really circuitous way to get a normal advantage die out of a Persona point instead of the usual artha die.

Shade Shifting Skills

Everyone knows the immense benefit of greyshading a stat before a skill: all future skills that you learn, rooted in that stat, will take on the same shade; but the skills you already learned will remain black. At character creation especially, this can be a game-changer (which is why Luke usually discourages it for low fantasy settings, but Loke is a high fantasy setting)! To better reflect this tone, I'm introducing the rule that if you have shade-shifted a stat and have a skill that would be rooted in stat but which isn't the same shade as the corresponding stat, you can spend time re-learning that skill: Removing it from your character sheet, going back to basics, and passing through the Beginners Luck aptitudes again. Alternatively, you can just accumulate Artha on the skill for a major epiphany as per the usual rules.

Character Burning

Clothes, Boots, and Sandals

'Clothes' and 'Shoes' cost 1 rps each in character burning. This distinction has always struck me as a little odd, so I'm giving a little benefit of doubt and also building some flavour in my world by just ruling that buying clothes will also give you a pair of functional sandals—which makes sense too, since most of Loke's climate is a bit hotter than on Earth. This way, "shoes" really means "boots". Boots are needed for long distance travel by foot, especially hiking: without them you'll suffer a double Obstacle penalty (like working without tools). Boots are also needed if you live in the colder climes. 'Finery' meanwhile, for 5 rps, is what will give you a proper pair of shoes!
Note: Not all stocks need shoes or sandals, and some don't even need boots. This will be noted in their racial traits.

Arms & Tools

Tool-kits are bought for specific skill-types. They cover all skills that your character knows at character creation for that skill-type. (In this sense 'Arms' can be thought of a tools for the Martial skill-type). The tool type is what then affects the cost: Travelling Gear, Basic Arms, and Simple Tools cost 1 rps, but you suffer a +1 Ob penalty when using them; 2 rps for Physical or Forester Tools; 3 rps for 'Poor-Quality' Arms or Peasant Tools; 4 rps for Artisan, Artist, Craftsman, or Seafaring Tools; 5 rps for 'Run-of-the Mill' Arms or Musical Tools; 6 rps for Academic and Military tools; 7 rps for Medicinal Tools; 8 rps for Sorcerous or Special tools; and 10 rps for 'Superior-Quality' Arms.
Note: Ranged weapons and armour are still the exception; they get individually priced as per the usual rules (BWG pg 202 for humans). Though shields can now be bought separately too for 1-4 rps (i.e. 1 rps per shield die). There are also some new ranged weapon options, depending on setting / location:

Simple slings cost 1 rps, war slings cost 3.

Blowpipes and spear-throwers each cost 3 rps.

Guns are still a pretty rudimentary science, taking the form of scatter guns costing 15 rps (c.f. pistols) and hand cannons for 20 rps (c.f. arquebuses). These guns have +1 IMS more than their normal listed values, but are heavy and unwieldy (two-handed) and dangerous (gunpowder die).

The 'dwarven slingshot' or stone bow is available for 6 rps.

And there is also a gastraphetes or 'belly bow' available for 10 rps: it has stats the same as a Great Bow except it only deals a Superb hit on a 6 and it reloads like a Crossbow.

Material Science

Loke is a largely bronze age world; or, in a certain sense one can almost think of it as being 'trapped' between the bronze and iron ages: always on the verge of scientific revolution but never quite reaching it. There is little shortage of iron ore in the world but there is almost no natural gas or coal, so getting fires hot enough to make crucible steel—without magic—is a very difficult and secretive art. Using magic for smelting is possible, but magic is a fickle beast, and magic is easily forgotten if not passed on. This leaves room for a lot of anachronisms, which is a nice writer's bonus, but it also means that by default all the metal components of your your weapons, tools, and armour are assumed to be made from high grade bronze or low grade iron.
Bronze, brass, and other copper alloys can all be made just as sharp as steel; they just bend and blunt a little easier, poor quality iron does too. As such after every conflict when you actually hit something with your weapon roll a Die of Fate: on a 1 the item has become 'bent or blunt'. This modifier simply means that it deals −1 IMS. To fix this, simply make an Ob 1 Mending test or an Ob 2 Soldiering test before your next fight. Bronze armour doesn't suffer this issue, instead if a steel weapon is used against bronze armour it gains +1 VA.
To start with steel gear—like damascus, mokume-gane, or wootz—that won't suffer the bending and blunting problem, and which gains +1 VA against bronze armour, simply double the base the rps cost of the gear (n.b. guns must be made of iron, but they fire lead shot, so this is already factored into their starting price and stats). Steel armour meanwhile is not grey-shaded, but it cannot be damaged except by other steel weapons or magic.
Note: if the item is already bent / blunt then it wont get any worse from further wear.

Skills & Traits

Appropriate Weapons

There isn't really a standardised list of weapons in Burning Wheel; which means a small problem can arise when you decide that "appropriate weapons" gives you the Polearms skill, say, and then someone else takes the Spears skill because a specific lifepath told them to. But isn't a spear just a kind of polearm? So let's reduce the ambiguity by making a standardised list of 18-24 martial skills, which will cover (almost) all bases. In the following list there is an explanation of what constitutes the skill, and a lists of example weapons from the real world that fall under the domain of that skill. Both one-handed and two-handed variants of weapons usually also fall under the same skill. Skill names with slashes (/) may be separated at the discretion of an individual GM.

Axes / Hammers / Picks
This skill covers the proficient use of any directional hafted chopping and thrusting weapons such as a: Warhammer, axe, warpick, poleaxe, bardiche, halberd, ji (dagger axe), panaba, maul, ōtsuchi, sparr, mattock, rungu (ball-club), woldo, war-scythe, eiku (oar-staff), kama, ono, lucerne, tsukubō, etc.
Root: Agility / Power
Blowdarts
This skill covers the proficient use of any mid-ranged projectile weapon that utilises the user's own breath as the source of propulsion, to send a (frequently poisoned) dart down a narrow tube and towards the target, such as a: Blowgun, blowpipe, blowtube, fukiya, etc.
Root: Forte / Agility
Bows
This skill covers the proficient use of any long-ranged projectile weapon that requires physical strength to draw on and hold still an elastic launching devise while aiming, such as a: Bow, longbow, daikyū, slingshot, cable bow, recurve bow, hunting or reflex bow, composite bow, gungdo, hankyū, etc.
Root: Perception / Power
Brawling & Savage Attack
These two skills cover all "undisciplined" rough-and-tumble wrestling, or tooth-and-nail, styles of combat. (Savage Attack is the animal version of Brawling. It covers the use of more intricate natural weapons like teeth, claws, and horns; but requires a special trait to learn). It is also the proficient use of any natural or improvised weapons, such as your fists and feet, or a: Shiv, broken bottle, chair, rake, blacksmiths mallet, pickaxe, lamp, garrote, corkscrew, stick with nails, fork, etc.
(Brawling can almost always be FoRKed into other close-combat martial skill tests, which represents dirty fighting, using everything to your advantage, and punching below the belt. Really, it's a question of sportsmanship and honour).
Root: Power
Chains / Ropes / Whips
This skill covers the proficient use of any hafted or hilted weapons on chains or ropes of metal or leather, such as a: Fail, whip, nunchaku, meteor hammer, manriki, kusari gama, chigiriki, sectioned-staff, chain whip, urumi, crop, cat-o'-nine-tails, flying guillotine, lasso, rope dart, bolas (monkey's-fist), etc.
(These are strong weapons, but absolute failure on a test with one results in the wielder hitting themselves; so these weapons aren't recommended for beginners).
Root: Agility
Cross Blades
This skill covers the proficient use of any bladed cut and punch weapons where the direction of the blade is perpendicular to the hilt such as a: Push dagger, katar, pata (gauntlet sword), dudley, ulu, scissor swords or hook swords, lùjiǎodao (deer horn knives), tonfa, bagh naka (tiger claws), lantern shield, hook, etc.
(These kinds of weapons are usually best used in pairs, and so Two-Fisted Fighting Training may always be FoRKed when duel-wielding.)
Root: Agility / Power
Crossbows
This skill covers the proficient use of any long-ranged projectile weapon that requires good coordination to draw on an elastic launching devise, which stores the kinetic energy once loaded until shot, and hand eye coordination to take aim and shoot, such as a: Crossbow, arbalest, lockbow, stonebow, gastraphetes, chuguo nu (repeating crossbow), etc.
Root: Perception / Agility
Cudgels / Staves
This skill covers the proficient use of any non-directional hafted smashing weapons such as a: Mace, morning star, club, sap, staff, baton, tetsubo, chuí, cosh, bō, shillelagh, gun stock, knobkierie, etc.
Root: Power
Firearms
This skill covers the proficient use of any mid-ranged projectile weapon that really only requires the dexterity to reload quickly under pressure, and the coordination to aim and pull a trigger or carefully lower a smouldering wick, where the source of the weapon's range and velocity is an explosive propellant, such as a: Gonne, pistol, musket, arquebus, flame piece, matchlock, blunderbuss, carbine, revolver, fire lance, flintlock, wheel-lock, huochong (hand cannon), rabauld, rifle, etc.
Root: Perception / Agility

Public Domain

Knives / Daggers
This skill covers the proficient use of any directional hilted short straight or curved bladed cut and thrust weapons such as a: Knife, dagger, shiv, tantō, bayonet (detached from a gun), kris, seax, flyssa, war fans, baselard, machete, short sword, cleaver, stiletto, scalpel, butterfly sword, kukri, etc.
Root: Agility
Lances / Pikes
This skill covers the proficient use of any non-directional very long hafted thrust-only weapons, and especially those best used while mounted, such as a: Lance, pike, konto, spontoon, man-catcher, pilum, yari, hay fork, sodegarami, etc.
Root: Agility / Power
Martial Arts
This skill covers all disciplined, trained and practised, styles of unarmed combat; and some specialised forms of armed combat. It also allows the character to use some special actions in Fight and Melee. Examples of real-world martial arts include: Boxing, Tahtib, Calinda, Krav Maga, Wushu, Tai Chi, Gatka, Aikido, Karate, Subak, Muay Boran, Savate, Jogo do Pau, Pygmachia, Kampfringen, Coreeda, etc.
Root: Agility / Power
Polearms / Spears
This skill covers the proficient use of any long hafted bladed cut and thrust weapons such as a: Spear, partisan, spetum, fauchard, runka, falxe, voulge, glaive, guisarme, ngao, podao, trishula (trident), bill, naginata, ox-tongue, qiang, bayonet (attached to a gun), sibat, sasumata, etc.
Root: Agility
Sabres
This skill covers the proficient use of any directional hilted long curved bladed cut and thrust weapons such as a: Sabre, scimitar, talwar, katana (and other 'nihonto'), falchion, messer, dao, khopesh, shotel, cutlass, dussack, shashka, etc.
Root: Agility
Slings / Spear-Throwers
This skill covers the proficient use of any mid-ranged projectile weapon that requires hand-eye-coordination and which utilises a soft or rigid tool as a source of leverage for extra range, such as a: Sling, pole-sling, atlatl, woomera (spear-thrower), lanyard arrow, war dart, kestros, bolas, etc.
Root: Agility
Swords / War Swords
This skill covers the proficient use of any directional hilted long straight bladed cut and thrust weapons such as a: Sword, long sword, arming sword, zweihänder, broadsword, rapier, spadroon, jian, khanda, estoc, spartha, chokutō, takoba, flamberge, bastard sword, etc.
Root: Agility
Throwing
This skill covers the proficient use of any short-ranged projectile weapon that uses the wielders own arm-strength and agility as the only source of propulsion, such as a: Rock, knife, hatchet, javelin, dart, vel, harpoon, phalarica, boomerang, rungu, pilum, chakram, shuriken, grenade, francisca, molotov cocktail, mambele, etc.
Root: Agility / Power

You may now be wondering what the point of learning to use an unusual weapon skill may be, such as "Cross Blades"? Well it's partly a cultural thing, to help flesh out the world. But also, since an opponent can always FoRK the weapon skill for a weapon you wield into their own attack (i.e. representing their knowledge of fighting with and against opponents who use the same weapon as you), using an unusual weapon reduces the chance of them being able to lever such an advantage. That also means, conversely, that in a sword vs. sword fight it all comes down to pure skill; rather than peripheral knowledge.

Bad Prophesies

The so called 'Astrology Die' can explode both ways infinitely; rather than infinite upward explosion but only one downward explosion as per the literal and admittedly very confusingly written original rules state. Astrology Dice from Help also behave this way—which can be thought of as you constructing a horoscope for someone before they do something—because it's more fun, but the Astrology skill itself does not.

Meditation Training

Meditation is now a 'Training Skill', meaning that it requires two points to open at character creation or must be learned during downtime in play. It also has no exponent and cannot be tested, ignore the obstacle list on pg 283. Instead Meditation now does two things:

It let's you meditate instead of sleep, and keep a perceptive ear out for danger; allowing you the benefit of a Perception or Observation test to break out of your meditative state before an intruder reaches you, for example. If the test is passed then you are instantly awake and ready to act!

Like the 'Care of the Eternal' (pg 141) your training gives you the patience of a saint, allowing you to work Carefully twice for a total of +2D, so long as you have the time to centre yourself, doubling again the time taken.

Aura Reading / Psychology

Aura Reading is a confusingly worded magic sub-system in Burning Wheel. The skill itself never explicitly tells you that it requires Second Sight or Magesense, but the Second Sight trait and the Magesense spell both say that they let you use Aura Reading. There's also a human trait called Touch of Ages, which does the same thing as a Dwarf-only skill called Reason of Old Stone; and some of their functionality is also covered by Aura Reading (i.e. seeing past / future events). Second Sight and Magesense both also seem to let you do some of the things that Aura Reading can do, but innate with Perception, and not all of them. Second Sight also makes Observation innate with Perception.
To top it off, there's also a poorly-named trait called 'Manhunter' that makes the non-magical part of Aura Reading innate with Perception! So if you had the Second Sight trait and the Manhunter trait you'd never need to ever actually open the Aura Reading skill, because all of it's powers will then be innate with Perception. It's like it's all part of an implied magic system that's never fully laid out for a player or a GM to understand or make use of, and the Codex does nothing to explain or expand on this system...
In Burning Sands there's a skill called Psychology that maybe offers an insight into the original intent of the system and possible solution to this mess: Psychology basically does everything that Aura Reading does in it's first set of Obs (i.e. the non-magical stuff like reading traits, instincts, motives, and to detect lying, etc.) but it cannot identify spells. Basically like the Manhunter trait, but as a skill. My suggestion to fix this is to let Aura Reading be a normal skill that anyone can learn (it can still be esoteric like Astrology, but not naturally open-ended), and have it work like Psychology.
Then, if the aura reader has Second Sight or Magesense they can literally see magic and auras and detect magic, and their Aura Reading skill becomes open-ended and the magic detection Obs are unlocked. Now, using either Perception or Aura Reading the character can use either to attempt to identify spells, using the same Obs for either method, but one method is naturally open-ended. This also means that someone with Second Sight or Manhunter but no Aura Reading can still make use of their expensive trait without also feeling the need to take Aura Reading.
Note: I also rule that magesense / second sight let you passively detect magic, and then test to actively identify that magic.

Commentary on Social Skills

So it seems like there's 3 broad social skills: Persuasion, Falsehood, and Intimidation. Interrogation is a strange mix of all three. Oratory, Acting, and Command are like the crowd-control versions of persuasion, falsehood, and intimidation (they use the most common Will in the crowd as the Ob). Suasion and Preaching are like religious versions of persuasion and oratory. Religious Diatribe seems like the religious version of interrogation or intimidation. Rhetoric is academic persuasion, or an appeal to logic, and incidentally uses the target's Perception as the Ob (not Will).
The description for Soothing Platitudes is a little bit of a joke, but in earnest I think the skill can be used to calm someone's nerves, make them feel better about themselves or their situation, and help them make good decisions; it doesn't have to be patronising. Haggling can be used negotiate, and Bargaining can be thought of a religious (or spiritual) Haggling. Begging is similar to both, but relates more to simple pleading (and can be a real life-saver in a fight). If Persuasion is an appeal to emotion, then Seduction can be thought of as an appeal to vice: avarice, indulgence, lust, vanity, etc. Extortion is kind of the opposite of all of this, it can be used to verbally kick someone while they're down, to strip their ego bare, or help them make bad decisions. Ugly Truth is like a weird mix of Extortion and Persuasion but it requires a real truth for it work, which is why the Obs are so low compared to other social skills. If a character is speaking truth but no one believe them, don't use Ugly Truth; use Persuasion, Begging, or Rhetoric instead.
Note: In a Duel of Wits these limitations on the use of each skill matters a lot less, what matters more is what you script and what you say and whether you have to right skill to back it up. I do believe that what you actually say, or role-play, and how you act matters less than what you roll—this is how we run fights after-all—but I do take it into account when determining what skill you should test.

Better Affinities

The 'Affinity for ..' traits and other traits that normally only give a single +1D bonus and cost 4 or more trait pts, instead grant −1 Ob to the test. (This is to make the trait feel more special and unique and worth the cost; especially since a −1 Ob bonus is a very rare effect normally, and any appropriate wise can grant +1D and is much cheaper).

Miscellaneous Skill & Trait Renaming

Conjuration ⇔ Sorcery ⇔ Summoning ⇔ Spirit Binding ⇔ Enchanting

Streetwise ⇔ Streetfly

Bee Husbandry ⇔ Insect Husbandry

Ditch-Digging ⇔ Digging

Taxidermy ⇔ Embalming

Two-Fisted Fighting Training ⇔ Two-Weapon Fighting Training

Mounted Combat Training ⇔ Combat Mount Training

Begging ⇔ Beggardry

Manhunter (Dt) ⇔ Sympathetic Nerve (Dt)

Rim of the Wheel

Adrenaline

When testing Steel for pain, make the Steel test before applying the wound. That is, Steel is still affected by any previous wound(s), but not the one you're about to get.
Additionally, getting wounded while already hesitating counts as 'changing the situation', even in a Fight, so the new hesitation result can override the previous one. This means that you can be stabbed once and hesitate for a long time, for example, then get stabbed a second time and get lucky and snap yourself out of the torpor; or at least change your hesitation action from 'stand and drool' to 'run screaming'.

Resources

The Gift of Kindness

In all cases where the Resources ability is used to represent liquid assets and simple monetary values, the Tax and 'the gift of kindness' should probably always be offered as the failure condition. That way the player can cut their losses and move on in especially bad failures. Traditional failure consequences and Tax for Resources can be interesting, but usually more so when the Resources ability is used to represent calling on favours, finding bureaucratic loopholes, and moving around fixed assets.

Lifestyle Maintenance

I tend to keep the lifestyle maintenance obstacles lower than the standard listings on page 372, because I prefer to use them as a base maintenance Ob set by your fixed assets and property, and then add penalties based on additional expenses per resources cycle. See Obs:

1. Shack / Homeless - Covers cost of food and basic necessities for one.
2. House / Shrine / Rent - Covers costs for a small family, or room and board for an adventurer and her steed.
3. Villa / Farm / Small Business / Workshop - Covers costs for a large family, standard work expenses, or keeping livestock.
4. Manor / Temple / Business - Covers costs for a small family with servants, advanced work expenses, or upkeep on an old building.
5. Keep / Small Estate / Large Business - Covers costs for a large family with servants, specialist work expenses (like overseas shipping), or upkeep on several buildings and a tract of land.
6. Fortress / Estate / SQ Workshop - Covers costs for a family with many servants, technical machine maintenance, or upkeep for many old buildings and a tract land
7. Castle / Large Estate - Covers costs for a large family with many servants and serfs or slaves, or upkeep for many buildings and swathes of land
8. Palace - Covers costs for a huge family with hundreds of servants and serfs or slaves, or upkeep for many old buildings and swathes of land

Reputation Clarification

Reputations can in certain specific scenarios be applied to normal ability tests too, not just Circles or Summoning. And if you know another character has a reputation, you can use it against them to find them with your own Circles skill (though this may require a pre-established fact, though play or with a wise). Also, strictly speaking, any Reputation may be considered 'infamous' by the right person in the wrong light. This is an independent consideration when a Reputation is used, but simply: It still let's you use the full +1-3D Reputation, you'll just suffer an additional +1-3 Ob penalty too.

Fight

Quantum Reflexes

If a character has Grey or White shades reflexes they get to script twice and choose their actual action after the volley is revealed. (Requiring a second script if both sides have quantum reflexes). This is as opposed to the usual rules where the Reflexes exponent just get multiplied by 2, which I think is way more over-powered. See my very long-winded analysis of the Fight mechanics for a full explanation on this one: https://www.reddit.com/r/BurningWheel/comments/9bkfvs/fight_a_dissection_of_terminology_reflexes_and/

Advice for Locks

When Locked you can still Fight, you're not immobilised, you're just reduced. The grappler takes the advantage at the hands Weapon Length if they successfully lock you; so, unless you're already at shortest WL, if you plan to keep striking while locked, it's probably a good idea to drop your weapon so that you don't suffer extra penalties. (Dropping your weapon is a free action). While being successfully Locked you will suffer a negative die penalty to all physical Stat tests and to martial, physical, and magical skill tests; this can increase further with marginal successes or by scripting more Lock actions to increase the pressure. Stat bases are not reduced for the purpose of calculating opposing Obs and Reflexes though. That is, pressure is not the same thing as a wound; you don't test Steel, and if the pressure is reduced the die penalty is reduced also (e.g. if you're Power is 4, and the pressure is at 2, his base Ob to Lock you again and increase the pressure will remain at Ob 2, rather than being reduced to Ob 1 if he had wounded you; and if you break out of the lock the pressure and it's accompanying -2D penalty are immediately removed).
Any pre-scripted Avoids will turn into Escape Lock actions instead—or if you weren't anticipating getting locked you can use the "Oh F∪¢κ!" rule on pg 457 to swap out your current action to an Escape Lock—which will reduce the pressure by 1 for each marginal success, but which uses another Physical stat—or the Escape Artist skill—instead of Speed, so always opt for your highest ability in this case. As soon as the pressure is reduced to zero, you've broken the lock, and if you have successes to spare you can even spend them to start Counter-locking. If the pressure is increased to the point that it equals your lowest physical stat then you are incapacitated and basically left to the mercy of the grappler (e.g. if Forte 4 is your lowest physical stat, then a pressure score of 4 will knock you out).
Locks are a great mechanic in my opinion—maybe the best implementation of a grappling system in any TTRPG I've played to date—it can often feel like bullshit to get Locked, but it's a legitimate strategy for anyone not skilled with melee weapons, and it really heightens the tension when a fight that started as an honourable duel devolves into a brutal struggle. The only really tricky part of the Lock is that the Brawling or Martial Arts skills can be substituted in place of Power, and in these instances you just have to remember that Avoid always ignores the double obstacle penalty for Stat vs. Skill tests; meanwhile, the opposite is not true if you're trying to break the Lock with Escape Artist vs. Power then you're opponent will be counting half-successes. So you're not at quite as much of a disadvantage as you might initially think. Locks are also a great way to have a fight without causing either side any serious harm, and so can be used to settle disputes quickly.

Shields

Shields in Burning Wheel are really complicated. Surprisingly complicated, given that they're just bits of wood and metal strapped to your arm. The standard rules have weird and seemingly arbitrary differences about using shields in different contexts. These rules aim to simplify them a bit:
Think of your shield as the first line of defence; the armour above your armour, so to speak. When you go to Block an attack—so long as it is not a Great Strike—after divvying up your attack and defence pools but before you and the opponent make a test, roll your shield dice against an obstacle equal to 1+ your opponent's weapon VA (just like armour). Success means the attack is blocked, and the action ends there with no test. Failure against a melee attack means you can now try to parry with remaining dice from your weapon skill pool too. Failure against a ranged attack means that it goes right through (n.b. recall that you can't normally block ranged attacks with melee skills). So long as your opponent actually hits you after dealing with this preliminary step: Subtract 1s from your shield dice as damage using the same 'quality' characteristics as armour.
The same rules work in Range and Cover, but remember that all ranged weapons are two-handed; so if you use a shield then you can't use a ranged weapon too.
Is all of this fair? Maybe not, but Burning Wheel has never concerned itself much with balance. Is it a helluva lot easier to work out? Yes, absolutely, because it uses basically the same system as armour; which we're all used to. Looking at it historically as well: shields only fell out of use once armour got cheaper and stronger; so it's on-brand for my world that shields should get a greater spotlight anyway.
Shields are an incredible offensive and defensive weapon, in the right hands. So what's the downside? The Clumsy Weight rules for Shields (BWG pg 482) reduce the advantages you can get for positioning, reduce your ability to grapple, force you to use one-handed weapons, and force you to use a shield with straps which makes dropping a broken shield require a physical action. Shield Training partly mitigates the Clumsy Weight by letting you use a strapless shield variant—meaning you can drop it as a free action—and may grant +1D to Forte test related to resisting exhaustion from using a shield. But mostly Shield Training does other things: it lets you script the Block & Strike action, and it lets you roll your shield dice (as above) for Counterattacks too, it also means that your Blocks can potentially stop Great Strikes (which they normally cannot). Finally, if you have shield training then you may use a shield as a weapon using the following stats:

Bucklers (1D): Power 1, Add 2, VA 1, WS 2, Shortest.

Targets (2D), Heaters (3D), & Towers (4D): Power 2, Add 2, VA 0, WS 1, Short.

This also means that you may test the Push or Charge actions at the short weapon length with a target shield or larger, if it is more advantageous for you to do so.

Streamlined Injury & Recovery

Note: Maybe this is less 'realistic' but I think it gives better control to the person with the injury, it might also help to make accidental injuries destroy the game's pacing a bit less often. It's also just as brutal as the old system.
For the sake of a sustained explanation, let's say that you the player character have just taken an injury. Health is tested to start the recovery process. The Health test can be made any time after the wound stops bleeding (which still requires a medical test) by resting for the night. Treatment is not a necessary component of the system anymore, but it can still give you bonus dice for the Health test, and it will remove the randomness from the recovery time. In other words, under this system, the effects of Treatment and the Health test are swapped: Treatment determines recovery time, the Health test determines recovery rate and long-term side-effects.
Obstacles for 'Staunching the Flow' and 'Treatment' are dependant on the medical skill used, given on pages 492 and 491 respectively. Attempting to recover without treatment sets a standard recovery time based on some DoF rolls (see below). By meeting the Ob, successes from the medical test will reduce the recovery time to the average of the DoF range [given in square brackets below]. Marginal successes from the medical test can then be added as bonus advantage dice for the patients Health test. However, if you seek medical help and the doctor gets absolutely no successes then they've botched the operation and this is worse than not getting treatment at all: Not only does the recovery take the full time, but the Health Ob is increased by 1.
The following lists the wound types and their associated base Health obstacles and recovery times, both with and without medical treatment. Marginal successes on the Health test can further reduce the recovery time by 10% per success, regardless of whether you got treatment or not:

Wound	Recovery Test (Health Ob)	Recovery time with Medical Success	Recovery time with No Treatment	Recovery time with Medical Failure
Superficial (+1 Ob)	Ob 1	—	A good night’s sleep	—
Light (-1D)	Ob 2	3 Days	1d6 Days	5 Days
Midi (-2D)	Ob 3	6 Weeks	2d6 Weeks	10 Weeks
Severe (-3D)	Ob 4	2 Months	1d6 Months	4 Months
Traumatic (-4D)	Ob 5	5 Months	2d6 Months	9 Months
Mortal (X)	Ob 6	1 Year	4d6 Months	1+½ Years

Successful Recovery

For all wound types, a successful Health test will remove 1Ob or 1D of pain after the first night's rest and ensure that there are no long-term conditions, scars, or debilitating traits; except for Mortal Wounds (see below). Afterwards, any remaining dice will be removed at regular intervals across the duration determined by the result of your of treatment test or by the die of fate, plus any marginal successes.

Failed Recovery

Failing the recovery test will result in different consequences depending on the severity of the wound, as follows:

Superficial

There are no long term consequences from Superficial wounds. Failure simply means you'll bear the wound for another full day; when you wake up the day after you'll be recovered.

Light

There are no long term consequences from Light wounds. Failure means that the wound lasts for the entire recovery time. That is, 1d6 days if you didn't receive treatment, for example.

Midi

Midi wounds bleed and must be staunched before a recovery can begin. If an attempt to staunch the wound is not started within a few hours (or before the end of the session) it will bleed out up to a Severe wound, and then stop bleeding. A failed recovery means that 1D is permanently removed from an appropriate stat, leaving a scar. The other 1D penalty is removed at the end of the recovery period.

Severe

Fresh Severe wounds bleed and must be staunched before a recovery can begin. If an attempt to staunch the wound is not started within a few minutes minutes (or before the end of the scene) it will bleed out up to a Traumatic wound, and then stop bleeding. A failed recovery means that 1D is permanently removed from an appropriate stat, leaving a scar, and that stat's maximum cap is permanently reduced by 1 Exp (represented with a trait). The second 1D penalty is removed half-way through the recovery period, and the last penalty is removed at the end of the recovery period.

Traumatic

Fresh Traumatic wounds bleed and must be staunched before a recovery can begin. If an attempt to staunch the wound is not started within a few seconds (or until the end of the exchange) it will bleed out up to a Mortal wound, and then you'll be dead! A failed recovery means that 1D is permanently removed from two appropriate stats (or 2D is removed from one stat) and those stat's maximum caps are each permanently reduced by 1 Exp (or 2 Exp for one stat). The third 1D penalty is removed half-way through the recovery period, and the fourth penalty is removed at the end of the recovery period.

Mortal Wounds

A Mortal wound means you're dead. There's no point in trying to staunch it, you're dead. If you have a Persona point then you can use it for the 'Will to Live'. (If you do this then the wound stops bleeding and you are guaranteed to survive, but it's a slow and gruelling process... think carefully before you vouch for your character's will to live): Regardless of success or failure on the recovery test, you will gain an appropriate injury trait such as: Missing Eye / Limb / Digits, Lame, or Disfigured, etc. Furthermore: A failed recovery means that 1D is permanently removed from two appropriate stats (or 2D is removed from one stat) and those stat's maximum caps are each permanently reduced by 1 Exp (or 2 Exp for one stat). A third 1D penalty is removed half-way through the recovery period, and a fourth and final 1D penalty is removed at the end of the recovery period.

Recovering from multiple wounds

If you're injured several times, then each wound needs to be recovered from separately (starting with the worst one). Only the worst injury needs to be staunched though. The injuries of different types all heal simultaneously, while injuries of the same type heal sequentially: meaning the recovery time is multiplied by the number of injuries of the same type. Making all the Health tests at once counts as a series test, so only mark the highest Ob towards advancement.

Example 1: You take two Light wounds, and a Midi wound, and successfully staunch the flow. You are unable to find treatment and so roll 6 days for the Light wounds, and a 1+2 = 3 weeks for the Midi. You fail both Health tests for the two light wounds, and so they'll only completely fade after 12 days rest; but you pass the recovery test for the Midi wound with one marginal success (-10%), meaning the first die penalty is removed after one day's rest, and the second goes away after 19 days.
Example 2: You take three Light wounds, and three Midis. One of the three Midis bleeds out to a Severe. You slip into a coma for weeks. You miraculously receive proper medical treatment for all your wounds, but get no marginal successes on your Health tests, totalling: up to 9 days to recover from the Light wounds, 12 weeks for the Midis, and 2 months for the Severe.

Fall Damage

In order to calculate falling damage, make an Escape Artist test at an obstacle roughly equal to the distance fallen in paces divided by 10 (up to a maximum obstacle of 10, at which point you reach terminal velocity). If successful, the character is knocked prone but miraculously sustains no injuries.
On a failure the surface that you land on is considered to have made a successful attack against you. If you're wearing armour then you can still choose which body part to land on (but that armour might also add to the difficulty of the tumble test above). The base Power of the attack is equal to the margin of failure from the Escape Aritst test and is further modified it by the surface you land on:

Water (−3 Pow) | Matting (−2 Pow) | Grass, dirt, sand (−1 Pow) | Wood flooring (+0 Pow) | Sheet metal (+1 Pow) | Stone or cobbles (+2 Pow) | Jagged rock (+3 Pow) | Spikes (+4 Pow). Then choose which body part is hit (with VA = 3) and roll a DoF (for IMS = 1-2/ 3-4/ 5-6).

Codex

See 'More Bloody Rules' pages 39-41. All of these rules are good and I like to use them; except for the stature rules.

Stature Rules

All told, there are nine statures. Associated with each stature is also a number. This number is a creature of that stature's base Mortal Wound (i.e. the number they must add their Forte to during character creation). The stature names, average heights, base MWs, and other benefits / deficits are as follows:

Minute: (<1" height): Base MW = 1 • Individual minute creatures cannot be engaged in combat • Swarms take on a higher collective stature.

Tiny: (1-12" height): Base MW = 3 • +4 Stride • −2 WL's • High Metabolism (Char)

Small: (1-3' height): Base MW = 5 • +2 Stride • −1 WL's

Diminutive: (3-5' height): Base MW = 6 • +1 Stride • −1 WL's

Middling: (5-6' height): Base MW = 6 • No major benefits or deficits.

Massive: (6-8' height): Base MW = 6 • +1 Ob to be Charged / Tackled, Pushed, or Locked by smaller creatures • +1 WL's

Huge: (8-10' height): Base MW = 7 • +1-2 Ob to be Charged / Tackled, Pushed, or Locked by smaller creatures • +1 WL's • Low metabolism (Char)

Gigantic: (10-20' height): Base MW = 9 • +1-4 Ob to be Charged / Tackled, Pushed, or Locked by smaller creatures • +2 WL's • Low metabolism (Char)

Colossal: (>20' height): Base MW = 12 • Cannot be Charged / Tackled, Pushed, or Locked by smaller creatures, must be Climbed instead • +3 WL's

There are also a few sub-categories for each: including Short and Tall, Stout and Slender (which is just my poetic way of saying endomorphic and ectomorphic). They have no major differences from the main stature though; they are just character traits for flavour (e.g. you can be Tall by Diminutive standards). Similarly High and Low metabolism are character traits which represent a need to always be eating or grazing.
Note: As the weapon length names 'shortest' and 'longest' imply, the minimum WL is 1 and the maximum is 5 (excluding missile weapons). There is no "longer than longest" or "shorter than shortest" because this just makes fights even more complicated than they already are.

Stride

Base Stride is independently determined by the creature's form of locomotion. For bipedal creatures this is a Stride of 7. If the creature has two or more forms of movement (like walking and flying) then the bonus from stature is only applied to one of those two forms. Recall that Stride isn't really your movement speed, it's a measure of your manoeuvrability. For a quick-and-dirty top movement speed calculation multiply your Speed stat by your Stride (in Km/h).

To see a stature comparison chart click here.