Bards channel their magic through their instruments, their voice or their song. One of the most classic examples of a Bard throughout history would have to be the pied piper, weaving his magic through his flute to lure away the rats from a local town and then later returning to lure away the children of the same town.
Your Bard doesn’t have to be a creepy weirdo, like the Pied Piper. But, they should be able to channel the power of their magic through their instrument or voice to influence the people and the world around them.
The Mechanics of Bard Spellcasting
A Bard at level 1 gets a choice of 2 cantrips and 2 first level spells to memorise and become “known spells”. Bards can only memorise a limited number of spells (as shown in the Players Handbook on page 53. Every time your Bard levels up they are allowed to learn 1 more spell, which they can choose from the Bard spell list on Page 207 of the PHB. Bards can also swap 1 currently known spell for another spell from the Bard spell list.
Bards use their charisma as spellcasting modifier, this means that on their spell attack roles they add their proficiency bonus and their charisma modifier to their roll any time the spell they cast calls for it. Bards also use it to calculate their Spell Save DC, which turns the tables and makes the enemy they targeted attempt to make a roll higher than the Spell Save DC to escape the damage. A bards Spell Save DC is therefore calculated like so, 8+ their proficiency bonus + their spellcasting modifier.
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