Quote Originally Posted by E’Tallitnics View Post
A48: No. There are no RAW that burden the DM with overlaying stat bumps on the fly.

Edit: By the way where are you seeing this? It’s not in the MM.
Quote Originally Posted by No brains View Post
Re 48
From MM342, top left corner:

Customizing NPCs
There are many easy ways to customize the NPCs in this appendix for your home campaign.
Racial Traits. You can add racial traits to an NPC. For example, a halfling druid might have a speed of 25 feet and the Lucky trait. Adding racial traits to an NPC doesn't alter its challenge rating. For more on racial traits, see the Player's Handbook.

To answer Mr. Adventurer, there is no need to adjust an NPC's ability scores. You should only do so if you feel the change would make a meaningful difference in the NPC's impression upon the characters.
FWIW:

I wouldn't be doing this on the fly: I prepare my encounters.

This isn't about need, it's about 'should'. Applying any racial traits to a "humanoid (any)" creature would be a straight upgrade, since they otherwise have no additional ability score points nor racial powers.

But at this point I think we are beyond the purpose of this thread.