Many questions have simple answers... If you have the appropriate reference at hand. But should we expect the DMG is ubiquitous? I know that at my AL table there are plenty of players with only the PHB, and some with only freely-available materials.
Many questions seem to be--at least, to a completist-- "Read the Book to Me Questions." But I wonder if they're not, instead, "I've downloaded and read the 114 pages of player's guide and even looked through the downloadable dm's rules. [63 pages, 55 of them monster/NPC stats.] Then I bought the Starter Set and got some more playing and GMing advice and content. So what the heck were the people at my table talking about?"
I'm so glad that with amount of content in the freely-available basic rules we can finally say to people with a straight face "you can play in--or even run and design--games for free." Then the starter set gives you a lot of good playing and GM guidance beyond that, for only 20 bucks. And "if you're serious about playing, obtain and read the PHB" is probably a fine sentiment.
I know we expect querents to do some research first. In the 5e world what should our expectations on resources be?
Possibly related: Should we prefer...Basic Rules or Player's Handbook