Strength

is one of the core player Stats. It plays a major role in determining the damage dealt by the player.

Mechanics
is one of the statistics in the damage calculation when using a melee or ranged weapon.

The formula is as follows:

$${\left\lfloor{\left(WeaponDMG + 5\right) \times \left(1 + \frac{STR}{100}\right) \times \left(1 + \frac{CritDMG}{100}\right) \times \left(1 + \frac{\text{Additive Multiplier}}{100}\right)} \right \rfloor = \text{Damage}}$$
 * WeaponDMG: weapon's damage stat
 * STR: strength (including base strength)
 * CritDMG: critical damage stat (including base critical damage)
 * Additive multiplier: combination of boosts from abilities and enchantments

Increasing Base Strength
At the start of the game, players have a base of 0. It can be increased by:
 * Leveling the Foraging skill
 * Turning in Fairy Souls to Tia the Fairy
 * Obtaining the Forbidden Strength upgrade in the Wither Essence Shop (from Malik in the Dungeon Hub)

Increasing Bonus Strength
There are several ways to gain additional bonus. These include, but are not limited to:
 * Most Weapons
 * Weapon upgrades
 * Hot Potato Books and Fuming Potato Books
 * The Art of War
 * Wood Singularity (Wooden weapons only)
 * Certain Armor
 * Certain Accessories
 * Certain Pets
 * Certain Reforges on items
 * Strength Potions
 * Weird Tuba
 * Training Weights
 * Power Orbs
 * Mana Flux
 * Overflux
 * Plasmaflux

History
力量 힘 Strength