@JeremyECrawford Suppose that I've failed the first Intelligence ST of the spell Mental Prison. Now I'm restrained, but I then use Dimension Door spell to teleport 500 feet away: I avoid the 10d10 psychic damage or the Mental Prison is teleported with me (is still around me)?

— Draconis (@DerynDraconis) January 10, 2019

If you move out of mental prison by any means, you take its psychic damage, and the spell ends. See the spell's final sentence for more details. #DnD https://t.co/OutBm4F7Uj

— Jeremy Crawford (@JeremyECrawford) January 24, 2019

Got home from work and only caught you guys signing off 😓 could you answer something for me as a post stream tweet? If a lvl 11 PC gets a sidekick, it would make sense for the sidekick to be lvl 11 right? Im hesitant cause it's a big jump both narratively and party balance wise

— Allie Deutschmann (@alliebug321) January 8, 2019

The sidekick rules were popular enough that I'm tinkering with a new version, in which your sidekick's starting level equals your level. #DnD https://t.co/kBlQwk8FWQ

— Jeremy Crawford (@JeremyECrawford) January 10, 2019

what do you mean the bugbear warrior doing 2D12 + strength damage with a great axe attacking 4 times a round and critting on 18-20 is too powerful? The actual fighter in the party loves being overshadowed! 😛 If a group has anxiety about their NPC companions doing well, I recommend not having NPC companions.

— Jeremy Crawford (@JeremyECrawford) January 10, 2019

It's not the group that's worried, its me, their DM. I don't want the npc's to outlast the players. They're the protagonists of the story.

— Rory Philstrom, DMDiv (@TheDMPastor) January 10, 2019

Some players love the feeling of being part of a group and celebrate the successes of its members.

Other players are all about the glory of their own character.

DMs, try to entertain both type of players, with moments for the group and the individuals in it to shine. #DnD https://t.co/ZaUXFDQOmm

— Jeremy Crawford (@JeremyECrawford) January 10, 2019

That collective celebration is best when you are celebrating the success of other PCs, those are your friends around the table. Celebrating the success of NPCs often feels like deus ex machina, leaving the people around the table sidelined while the DM plays with themself.

— Rory Philstrom, DMDiv (@TheDMPastor) January 10, 2019

There is an important distinction between an NPC controlled by the DM and an NPC controlled by the players.

The DM-controlled character/critter is rarely viewed as a party member.

But a player-controlled character/critter is often just as loved as a PC. #DnD https://t.co/oiuxogNJBO

— Jeremy Crawford (@JeremyECrawford) January 10, 2019

Yes, strong sidekicks can work if player controlled. But they’re basically a second character then, more of a hireling or follower from old ad&d, than a non-player character. Agreed. You just described the new sidekicks.

— Jeremy Crawford (@JeremyECrawford) January 10, 2019

That’s just simply not true. I mean it’s like a half-truth. The distinction is only real if the players allow it to be real.

Pretty much everytime I introduce an NPC…my players want he/she stat blocked and leveled so they can refer to it if need be. If the players are using the stat block of a character/critter, that's what I mean by player control. Sometimes that turns into co-control with the DM. Either way, they're invested.

— Jeremy Crawford (@JeremyECrawford) January 10, 2019

How opposed are you to NPCs leveling with players? Not opposed at all. I've provided rules in the "Dungeon Master's Guide" and in the recent "Sidekicks" article that level up NPCs.

— Jeremy Crawford (@JeremyECrawford) January 10, 2019

Speaking of concentration,

If you're concentrating on a spell (i.e. Delayed Blast Fireball) & you cast another conc. spell, does the first spell end *immediately* upon casting, or does end once the second spell's effects activate – lingering until you begin concentrating?

— Slayer Kast (@SlayerKast) January 10, 2019

@JeremyECrawford Shadow of Moil spell makes the warlock heavily obscured, but the "flame-like shadows" that heavily obscure only the warlock are physical concealments (like flames/smoke) or are mundane shadows (so darkvision lets see the warlock in shades of gray)?

— Draconis (@DerynDraconis) January 10, 2019

Shadow of Moil heavily obscures you, full stop. The spell also dims the light around you.

The fact that you're heavily obscured is a result of the flame-like shadows surrounding you, not the result of being in darkness. This means you're heavily obscured even to darkvision. #DnD https://t.co/dEAZRZsjLi

— Jeremy Crawford (@JeremyECrawford) January 14, 2019

@JeremyECrawford Do Mastery of Death or Strength of the Grave function like Death Ward or like Relentless Endurance when it comes to being Disintegrated? I.E. Can they be used after being reduced to 0 or are you disintegrated?

— Eric Green (@quadhund) February 19, 2018

Mastery of Death and Strength of the Grave can be used when you drop to 0 hit points. They don't care how you got to 0. #DnD https://t.co/G6PTnsub45

— Jeremy Crawford (@JeremyECrawford) February 22, 2018