Another discovery I made working on the beginner’s rules document mentioned in my post about Half-Elves was that it could use some overview on the playable races and their place in the world(s) of D&D. (Any rules mentioned represent the way I prefer games of D&D to be handled; they are of course not set in stone.)
Common. The most common races, found all across the world. People are usually accustomed to meeting you and will treat you well (if you don’t piss them off). Feel free to choose any of them, your DM won’t complain. Probably.
(Dwarves, Elves, Humans, Halflings)
Uncommon. Even if somewhat more withdrawn, these races are still seen quite often. You shouldn’t run into too much trouble because of your race, but some people might be prejudiced against you. Your DM will very likely allow you to play one of them, but might ask for a specific reason for your character to go out adventuring.
(Gnomes, Half-Elves, Half-Orcs, Dragonborn, Tieflings)
Rare. When playing as one of these races, you can expect people to stare at you or even whisper behind your back – they’ve probably never seen anyone like you before! They might also be somewhat reserved, but will mostly treat you with respect, provided you do the same. Your DM might ask for a nice bit of backstory to explain how you’ve become an adventurer, but (hopefully) won’t object.
(Aasimar, Firbolg, Gith, Deep Gnome, Goliath, Ghostwise Halfling, Tabaxi, Tortle)
Exotic. Now, here’s where it gets difficult. Members of these races are a lot less common, and people will be very suspicious about your intentions. They’ve only heard of your kind in stories, some of which might not exactly help your reputation. You can expect to be searched a lot, and most people will be highly apprehensive around you. Double check with your DM before choosing, and give a good reason to do so.
(Aarakocra, some Elves, Genasi, Kenku, Lizardfolk, Triton)
Monsters and Evil Variants. Oh boy. If you’re looking for a challenge, you’ve come to the right place! Races generally viewed as evil or monsters won’t sit well with most common folk – they probably won’t even let you into their villages or cities, and might attack on sight. Convincing them you don’t mean any harm will be hard work, and that’s if it’s even possible. Definitely talk to your DM before choosing, and work together to create a legitimate reason for your character to go adventuring.
(includes Bugbears, Centaurs, and Kobolds, amongst others)
Other Settings. These races don’t usually appear in the world at all, and people you meet won’t have any clue as to who or what you are. Their reactions are quite unpredictable, you might encounter anything from mild curiosity to outright hostility. If your mind is set on playing as one of them, talk to your DM and give a good reason; chances are, they’ll have to adjust their campaign/worldbuilding a bit to make it happen.
(Races from Guildmasters’ Guide to Ravnica and Wayfinder’s Guide to Eberron)
Unearthed Arcana and Plane Shift. Only use these if you can’t find anything else that fits your needs and/or backstory. The reception of these races depends highly on the chosen race, the world you play in, and your DM. These are races that are still considered to be in a playtesting phase, and so your DM might make some changes to integrate them into the world and balance them in combat. Be prepared to adjust your character during the course of the campaign, if it is deemed too unbalanced.
(Races from various Unearthed Arcana documents and Plane Shift: Zendikar)