Start With Weapon Proficiency (5e Variant Rule)
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During character creation, you can choose to reduce your Dexterity score by 2 to gain proficiency with all simple and martial weapons.
This sacrifice represents deliberately training with many different kinds of weapons throughout your early years. This was probably against inanimate targets which don't fight back, at the cost of more varied experiences using your hands for other dexterous tasks—likely including defense against monsters that actually hit back.
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