Many RPGs, particularly fantasy and sci-fi games have multiple races for characters to be, and some of those races have racial prejudices built in. This leaves the games open for having issues that are drawn along race relations come into the game. How you handle that depends on your table, but it's worth bringing up. Today I want to talk about that.
Everyone Hates The Drow
D&D 5e has a long list of potential races players can be, and on that list are several races that are widely considered evil in the black and white type morality that D&D holds. Players can find rules for being Drow in the base Players Handbook, and there are rules for numerous "monster" races including goblins, orcs, hobgoblins, and bugbears in Volo's Guide To Monsters. The monster races have a side bar warning that players taking those races should be prepared for negative reactions, but the same level of care is not taken with Drow.
This puts a burden on the GM that should be handled at character creation. It's not a huge burden thankfully. It simply is that you should warn players taking races like the Drow or goblins that certain things could be harder for them because of that race. In fact....
A Needed Conversation
Frankly, you should know as a GM before anyone makes a character if you're ok or not ok with things like racism in your game. Are you ok with a town, city, or country and the people inside it having a negative reaction to a PC because of race? If not, you should let your players know. If so, you should check with your players if they want those things in the game. Social situations like what can come up with racism are not what everyone is looking for, and the players should have just as much right to veto as the DM does.
If the players don't want it in the game - or you as the GM don't - then you need to decide if those races are still allowed in the game. It's not a huge problem either way. They're not allowed, and you're free to play up the stereotypes of those races as evil. Alternatively, they are allowed and all it means is that while people do know drow tend to be evil, they also know an individual isn't bound to that and so will get a chance. Not very "real world" but it's a fantasy universe, we can have social ideals.
Use It Early, But Use It Rarely
If you are having race dynamics in your game, you want to bring it up early in the game. Why? Because then it is part of the core of the world when the players are forming it in their head. If the players have first impressions including being careful about race, those impressions will carry with them.
However, once you establish the existence, take care to not overdo it. It is one thing for a character to be mistrusted or hassled here and there. It is another for every time something social is coming up that the race part takes everything over. This doesn't mean you can't use it. Just be aware of it. Your world will have people who act on those impressions based on the race stereotypes. It should also have some who don't.