Weapons in Dark Souls: PtRE have varied and powerful movesets, allowing one weapon to be used in a number of different ways that can help in different circumstances. If the character is two-handing a weapon, their strength is considered 1.5 times their ability score when seeing if they pass the requirement. You must pass the requirement to use any attacks bar the standard strike and to gain STR/DEX bonuses. You must pass 2/3 of the requirement (eg. 16 STR for a 24 STR requirement) to wield the weapon regardless.