Base Raw refers to the amount of raw damage present on the weapon itself. Base Raw is exclusive to the weapon.

Note that some games have Bloat, meaning that weapon stats are multiplied by some number Capcom deems good. Most good resources show Base Raw alongside Bloated Raw where applicable. Typically, the only possible Base Raw increases stem from Augments and Augment-Like systems, such as Qrafting for Weapons in Sunbreak, or Augments and Custom Augments themselves in World.

Base Raw = Base (weapon) + modifiers

Raw % refers to everything that grants raw based on Base Raw. Examples of this are Attack Boost from Rise onwards, Heroics* (armor skills) and Adrenaline* (food skill).

Some sources of this are game specific, such as Power Phials and Attack Up Songs in Wilds. Additionally, all those sources scale multiplicatively, so gaining 10% - or a multiplier of 1.1 - from Attack Boost and 30% - or 1.3 - from Heroics results in a total modifier of 43%, or 1.43.

Raw % = Source 1 x Source 2 x Source 3…

Whenever something adds a specific amount of raw, it is applied in the Flat Raw bracket.

Examples of this are armor skills such as Attack Boost and Burst, but also Power Charm/Talon, Might Seed, certain gesture-dependent Food skills, and using Meat as an ingredient in Wilds specifically.

Flat Raw = Source 1 + Source 2 + Source 3…

Post-Modifiers are relatively rare and are applied at the end of (Raw) Damage Calculation. Sources for this type of modifier depend on the game.

Pre-Wilds, Power Phials acted as such. Other examples are Frostcraft, Grinder (s), Anti-Species and Silkbind Boost Rampage skills. Similar to Raw%, these apply multiplicatively.

Post Raw = Source 1 x Source 2 x Source 3…

Motion Value (MV) is the term used to refer to how strong specific weapon attacks are.

These are usually given as a percentage; an attack with a motion value of 24 would do 24% of the true raw if there were no other modifiers.

MV can typically be found in datamines, or on one of the more accurate calculator sheets and websites.

Affinity is the weapon stat that governs your critical hit rate. It can be positive or negative. Negative affinity results in critical failures: if your weapon has -30% affinity, that means that there is a 30% chance to do less damage than usual.

By default, in Monster Hunter Wilds, crits do 25% more damage, and negative crits do 25% less damage. The amount of damage critical hits can do is affected by the weapon skill “Critical Boost.”
The damage modifiers for each level of Critical Boost in Wilds are shown in the table below. Critical Boost doesn’t change the damage of negative crits.

To estimate the amount of damage that your affinity will contribute to your weapon’s overall damage, calculate a weighted average of damage for non critical hits. For example, if you have 95% affinity with Critical Boost 3 in Wilds, since you aren’t critting 5% of the time, you would get a average critical modifier of

1*0.95*1.34+1*0.05 -> (1+(0.34*0.95)) = 1.323,

so a weapon with 100 true raw would on average be doing as much damage as a 132.3 true raw weapon without affinity.

There are some important caveats.
The first is that some attacks are unable to crit at all, and so do not benefit from having higher affinity whatsoever.
These tend to be fixed damage hits like Gunlance shells.
Fixed damage is rare enough that most weapons and playstyles benefit greatly from building affinity sets, but others get next to no benefit because so much of their damage comes from these fixed attacks.

The second is that there is no benefit to having more than 100% affinity. As a result, you should try to tailor your sets to not go over 100%.

The last is that most skills have uptimes; while some give you affinity consistently, like Critical Eye and Weakness Exploit, others, like Agitator and Latent Power, have unavoidable periods where they give you no affinity. If you want to be especially accurate in your calculations, you will need to calculate your average affinity by multiplying the affinity given from the skill by the percentage of the hunt it’s active. Unfortunately, this changes based on skill, matchup, weapon and playstyle, so you will need to determine this for yourself.

Sharpness is a Post-Modifier. Technically speaking, it acts as a Hitzone Modifier, i.e. (Hitzone x Sharpness). Note that the specific values sharpness provides can vary on a game-by-game basis, especially in older entries. Sharpness applies as a flat number modifier, e.g. … x 1.32 … for White Sharpness.

Gunner Weapons, Bow and both Bowguns, typically don’t use sharpness at all.
Not all moves scale with sharpness either, like some instances of Zero Sum Discharge for Switch Axe, Shells for Gunlance or SAED Phials for Charge Blade.

Telling which moves do and don’t scale with sharpness can often easily be gotten from dedicated MV Sheets and Infodumps, or by testing.

Hitzone Value is the modifier associated with the part of a Monster that is hit by an attack. They can be thought of as a monster's defenses. These numbers can be found on dedicated sheets and websites, as well as some adjacent online tools such as some damage calculators or builders.

Similar to MV, they are effectively % values. They interact with certain skills such as Weakness Exploit and Mind’s Eye (as a condition to apply these skills), and can be affected by Tenderizing (World/Iceborne), Waterblight (Rise/Sunbreak), and Wounded State (Wilds).

Attacking a hitzone of 50 means 50% of your previously calculated raw damage gets dealt to the monster, a hitzone of 20 translates to 20%. Different damage types have different hitzone values, meaning a monster may have different weak points for slash, blunt and shot.

Note that in some games, bouncing applies an additional penalty to (raw) damage dealt. Bouncing is determined by Sharpness Modifier x HZV, on a per-game-basis.

Base Element refers to the amount of element present on the weapon itself. Base Element is exclusive to the weapon.

Note that some games have Bloat, meaning that elemental stats are multiplied by 10. Unlike Bloated Raw, this is consistent across weapon types.
Typically, the only possible Base Element increases stem from Augments and Augment-Like systems, such as Qrafting for Weapons in Sunbreak, or Augments and Custom Augments themselves in World.

Base Element = Base (weapon) + modifiers

Ele% refers to everything that grants element based on Base Element. Examples of this are Element Attack, and Coalescence. Some sources of this are game specific, such as Element Phials and Element Up Songs in Wilds.
Additionally, all those sources scale multiplicatively, so gaining 20% - or a multiplier of 1.2 - from Element Attack and 10% - or 1.1 - from Coalescence results in a total modifier of 32%, or 1.32.

Ele% = Source 1 x Source 2 x Source 3…

Whenever something adds a specific amount of element, it is applied in the Flat Element bracket. Examples of this are armor skills such as Burst, or the Rise and World variants of Element Attack.

Flat Element = Source 1 + Source 2 + Source 3…

Post-Modifiers are relatively rare and are applied at the end of (element) Damage Calculation.

Sources for this type of modifier depend on the game. Pre-Wilds, Element Phials and Charge Master acted as such. Other examples are Frostcraft, Element Exploit both as Armor and Rampage Skills. Similar to Ele%, these apply multiplicatively.

Post Element = Source 1 x Source 2 x Source 3…

Elemod is the term used to refer to how elementally strong specific weapon attacks are. These are usually given as a decimal, most commonly smaller than or equal to 1;
an attack with an elemod of 1 applies 100% of the Weapons element against a target hitzone. An elemod of 0.35 applies 35%, and an elemod of 1.5 applies 150%.

Elemod can typically be found in datamines, or on one of the more accurate calculator sheets and websites.

Elemental crit works similarly to raw crit, but there are some important differences. By default, critical hits do not increase the amount of elemental damage you do, only raw damage.

In order for a critical hit to affect elemental damage, you need to have the weapon skill “Crit Element”. Similar to Raw, once Crit Element is used, its modifier applies as a multiplier at the end of the Damage Calculation.

Otherwise, the same benefits and caveats apply as the raw section. If you were running a 95% Affinity Long Sword with 28 Element and Crit Element 3, that would result in a modifier of

1.15*0.95+1*0.05 = 1.1425,

resulting in you doing as much damage as a 32 element Long Sword on average.

Elemental damage is affected by sharpness in basically the same way as raw damage, but has different modifiers.

Note that the specific values sharpness provides can vary on a game-by-game basis, especially in older entries.

Hitzones function the same way for element as they do for raw, but again have separate values. In fact, each element has a separate value! Monsters are not as uniformly weak to elements as the Hunters notes may imply.

For example, Rey Dau’s head (his weakest, read: best elemental hitzone) has a hitzone value of 25, but his legs are a 5 ice hitzone, meaning that your ice damage will be only ⅕ as effective if you hit his legs.

A monster may have different weakest hitzones for raw and element, as well.
Rise's Crimson Glow Valstrax for example has a 55 (cut) hitzone at its head, but when it enrages, it becomes immune to element except on its forelegs, which are only a 25 (cut) hitzone, but 25 for every non-dragon Element.

Applies to Sword and Shield, Lance and Gunlance.

Sometimes, Shields scale with sharpness. In cases where they do not scale, they use a predetermined Sharpness Modifier, which is often either found in datamined sheets or via testing.

Typically, they do not deal element damage but can contribute KO and Exhaust and do not consume sharpness.

In older games, Gunlance shells and other explosives dealt fixed damage that ignored raw hitzones.
In Wilds, Gunlance shells now scale with raw attack, but not sharpness, and still ignore hitzones.

Weirdly, in both Wilds and older games, shells have a small fire damage component that does interact with the monster’s fire hitzones, making shelling slightly more effective against fire weak monsters.

The amount of damage is tied to the Gunlance’s shelling type and level, and can be increased with the Artillery skill.

This applies to Switch Axes Phial Ticks (introduced in World), as well as Charge Blades Phials.

Sometimes they scale with sharpness, sometimes they don’t. Typically, SAED Phials cannot crit and don’t have a standard MV attached, in exchange for huge Elemod instead, and tend to not scale with sharpness.

Switch Axe Phial ticks can crit in World and Wilds, but not in Rise.
Additionally, Switch Axe Phials can apply as base modifier like in Wilds, or as post modifier like in Rise. In older games, they can act as MV modifiers specifically, which is important for things like clearing Frenzy. Additionally, Status Phials in Wilds break the standard 10/30 convention of applying Status and guarantee them instead.

Both Charge Blade and Switch Axe are capable of inflicting exhaust and KO, depending on Phial Type - Impact and Exhaust respectively.

Bowgun ammo and Bow shots typically don’t have sharpness values attached. Instead, they operate on Critical Distance, which is a negative modifier of 1 while it applies, and gets lower in (game-dependent) tiers depending on how far out of range you are.

Sometimes Super Critical Distance is an additional tier, which typically is a modifier greater than 1. Critical Distance technically is a MV modifier.

Guns do not have an element stat and scale off of their raw stat instead, even for elemental ammo, which functions similar to Gunlance shells' innate fire damage.
Elemental ammo has matching innate base element damage attached.
Additionally, a lot of damage comes from repeated ticks in cases such as Pierce projectiles, which have their own variance such as FPS dependent calculations, or entering/exiting hitboxes depending on the specific line taken.

Some ammo types behave differently depending on the game. An example of this is the old Normal 3 ammo, which would bounce around, introducing a different type of variance than Pierce. Bow additionally sometimes has charge modifiers attached, similar to Greatsword (but not necessarily applied as an extended hitzone modifier).

These differences can only accurately be determined by rigorous testing, and as such are often just available in dedicated communities.

Echo waves are a Hunting Horn mechanic in Iceborne and Wilds. They do not scale with sharpness.

In Wilds, they behave like Bowgun ammo, meaning they scale off of the raw stat even for elemental waves. The status waves deal a fixed amount of status and are guaranteed to do so like Phials.
However, while they do not scale with the weapon’s base element or status, buffs that increase element or status do increase the amount of elemental damage or status that they do.

Most echo waves cannot crit, except for Echo Wave (Slash). Echo waves interact with hitzones as normal.

Some skills provide damage directly, but in ways that are not a direct part of your weapon damage calculations.
Examples of this type of skill include Powder Mantle from Sunbreak or Flayer from Wilds.

Some skills are moved around in the Damage Calculation from game to game as well, sometimes applying as base, sometimes as post, and sometimes getting different effects altogether. This can usually only be determined by rigorous testing.

Much like Hunters, in some games, Monsters have a defense Value too. Specifically, a defense modifier.
A modern example of this is World. Damage gets calculated against that defense modifier. These modifiers typically vary between quests, like in World Investigations.

Sometimes these values swing between 0.97 and 1.03, some more extreme Examples are present in Frontier, where they can go all the way to 3%, meaning you only deal 3% of the damage you should be dealing.
Sometimes, Poison specifically gets around this modifier, often making it reasonably strong in those games.