Dwarven Commonality. In a world mostly defined by dwarves, Dwarven has naturally replaced common. Whenever a feature would grant you the Common language, replace it with Dwarven. If you already speak Dwarven, choose another language.

Alternative Ability Checks. You may be able to use a different ability score than the default when making a skill check. Examples include STR (Slight of Hand) to pick a lock McNally Style, WIS (Investigation) to disbelieve an illusion, CON (Intimidation) to Intimidate by a physical display, etc.

Alternative Casting Abilities: Warlocks, Druids, Sorcerers and Rangers may choose to use Intelligence as their key ability score rather than their default. This changes class features and spellcasting to reference intelligence instead of wisdom or charisma. A druid/ranger who casts spells this way is considered Arcane, rather than Primal/Divine.

Versatile Bards. Bards may be of any performing art, rather than just music. The bard must take proficiency in a relevant performing tool (A sword-swallower might take proficiency in Smith's Tools instead of a Lute, etc)

New Skill. Intelligence (Science)