D&D 5E Beginner question / ability check + proficiency bonus

[Hrothgar Rannúlfr]

Why wouldn't it apply to attacks with weapons your character wasn't proficient in using?

 

[Paraxis]

Why wouldn't it apply to attacks with weapons your character wasn't proficient in using?

Because attacks are not ability checks.

There are three kinds of d20 rolls in 5e; Attacks, Saves, and Ability Checks. For example the guidance cantrip only effects ability checks so it doesn't give you a bonus to attacks or saves, same thing with the bard ability.

 

[Hrothgar Rannúlfr]

Thanks, Paraxis. I found the relevant language in column 1 of page 173 of the PHB or page 57 of the Basic Rules, where it clearly explains that attack rolls and saving throws are not ability checks.

 

[psiconauta_retro]

Thanks to everyone, it has been very interesting and my doubt has been fully clarified!