Proficiency, or prof for short, is a numerical value on an equipment that shows how long the item has been used in the current state. It is needed in order to perform upgrades. Proficiency only decreases when it is used in upgrades.
Proficiency is shown as XX(xx.x%) in game. To evaluate the total proficiency of an item, this can be simply interpreted as [XX.xx]%, where [101.00]% or 100(100.0%) is the maximum proficiency that can be achieved on an item. When the number in the parenthesis reaches +0(100.0%) the digit outside will go up by one and will automatically be +1(0.0%).
To gain proficiency from a monster, the monster's Combat Power level must be ranked as Weak or higher; Weakest monsters will not yield any proficiency for weapons or shields when used offensively. This does not affect shields when used defensively nor armor/clothing, however.
Fighting in PvP does not yield proficiency.
- Weapons earn proficiency through each hit.
- Wands and Staves gain proficiency from using magic as well as when used as a melee weapon.
- Cylinders will gain proficiency by using offensive alchemy skills as well as when used as a melee weapon.
- Skills that hit multiple times (e.g. Thunder, Flame Burst, Somersault Kick, Pummel, etc.) will give proficiency for each successive hit. Hitting multiple targets with one attack (e.g. Weapon Splash, Windmill, Fireball, Ice Spear, Heat Buster, Drop Kick, etc.) raises proficiency only once per attack, regardless of the number of targets hit.
- However, if the player is Dual Wielding and only hits the target once rather than twice (e.g. on the final blow or attacking a target using Defense), only the weapon in the off-hand slot will gain proficiency.
- If a player is Dual Wielding and using normal attacks, the weapon in the off-hand slot may gain proficiency slightly more frequently.
- However, if the player uses single-hit skills instead of normal melee attacks, both weapons will gain proficiency at once.
- When using a bow to fire arrows, the proficiency gain is based on the "Ranged (%)" column. However, when using Close-combat skills such as Windmill or Counterattack, the bow proficiency gain is based on the "Melee (%)" column.
- Assault Slash and Doppelganger do not yield proficiency.
- Armor/Clothing earn proficiency through the wearer being hit and from simply being worn.
- When wearing the armor/clothing, it will gain the amount of proficiency listed in the "Damage(Time)(%)" column in parentheses every Tick.
- When attacked, armor/clothing may gain the amount of proficiency listed in the "Damage(Time)(%)" column outside parentheses with each hit.
- Wearing other equipment may prevent the armor/clothing from getting proficiency. 
- Shields earn proficiency through successfully defended attacks, as well as from simply being worn.
- When the shield is in an active equipment slot, it will gain the amount of proficiency listed in the "Damage(Time)(%)" column in parentheses every Tick.
- When an attack is defended with the Defense skill and a shield is equipped, it will gain proficiency according to the "Defense(%)" column.
- A shield may randomly gain proficiency if it is in an active equipment slot and the user is hit. This chance is dependent on how many other armor items are being worn (any equipment slot excluding weapons)
- Shields also gain proficiency by attacking with the Charge skill.
- Guard Cylinders gain proficiency in a similar matter to shields and cylinders.
- Gathering Tools earn proficiency through use of the item with Gathering or Life Skills.
- Proficiency is still given even if the gathering attempt fails, even if this is because the object has been depleted of resources.
- Instruments gain proficiency at the start of playing any music, and also when used as melee weapons.
- Song does not yield proficiency.
Equipment Proficiency Chart
|Age||Melee (%)||Ranged (%)||Gather (%)||Music (%)||Damage (Time) (%)||Defend (%)|
- Players with Premium Service may receive 2.5x as much proficiency.
- Players gain 1.2x as much proficiency on Thursdays (this stacks with Premium Service).
- Defend (%) refers to blocking an attack with the Defense skill while a shield is equipped.
- Only gathering tools gain the full gathering proficiency. For example, a Gathering Knife gets the full gathering proficiency when shearing a sheep but using a sword will only get a fraction of that (these are the numbers shown in the parentheses).
Proficiency Training Tips
- Each time you are hit, a random non-weapon piece of equipment is chosen to take durability damage, and, if applicable, gain proficiency.
- Proficiency is given regardless of the song difficulty when playing. In fact, 0.3 or 0.6 proficiency is given at the start of the music. Therefore one may alternate between the skill hotkey and the 'cancel skill' hotkey. It is not necessary to finish playing the song to accumulate the points.
- Proficiency is received as if it were a melee weapon which can be much faster than alternating the buttons for play/stop playing. It also uses up less durability.