Mike Mearls, sometimes "Mike Meals" because as you see from the photo the man hasn't missed many of those, is a designer for Wizards of the Coast. He became lead developer for Dungeons & Dragons 4th Edition in 2009 and co-designer of Dungeons & Dragons 5th Edition - before Monte Cook quit due to "personal differences".
Over the d20 era Mearls' earlier work includes Portals & Planes for Legends & Lairs. He further worked closely with Monte himself on Arcana Unearthed - which limits he tested, such that Malhavoc stuck his ideas in separate books not cited by any AU author named other than "Mearls".
On the Mearls / Cook split in 5e, Cook stated "I want to take this time to stress that my differences were not with my fellow designers, Rob Schwalb and Bruce Cordell. I enjoyed every moment of working with them over the past year. I have faith that they'll create a fun game. I'm rooting for them." The community noticed the omission of Mike Mearls in this statement and assumed this was due to the rumored friction that resulted in Cook's departure. Fans disagree on whom was at fault in the apparent disagreements between the two. Mearls' recent move from lead developer on 4th Edition to co-designer in 5th Edition is considered a demotion. That would imply that senior members like Chris Perkins saw decisions made by Mearls during 4th edition as a detriment to the game. Recent comments by Mearls suggesting the removal of mechanics like bonus actions the resulting negative reactions by fans suggest this demotion was just, as the general consensus that removing such a key component of the game would break many of the classes who rely on it (the implication that people who opposed such a move were misogynist "gatekeepers" didn't win him any fans). He considers 3rd edition and 4th editions to have a "fatal flaw" of being too modular. People wouldn't really care about this, but his lead in was saying people who liked such a thing were "assholes" and "obnoxious people" while games with such were a "game for assholes".
This has nevertheless not stopped Wizards of the Coast from granting Mearls leadership on projects such as the recent "Guildmaster's Guide to Ravnica", no doubt to keep him busy while members like Perkins do the real work. Politics aside, most would say he is batting .500 as 4e is skub where 5e has earned some tentative acceptance by fans. Mike made a deal with Tzeentch to create the "Essentials" line, and his stretch as the lead designer of "Guildmaster's Guide to Ravnica" produced a roughly 50/50 split of acceptance among fans (in what appears to be a theme for his work), since he appeared to be making a second attempt at associating D&D with a card game, the first time being 4th edition.
What he claims is his design philosophy is inspired by the first few editions of the game, which found expression through 5e's many "throwback" game mechanics, and the "Essentials" line's pared-down design. He's also been writing the Unearthed Arcana articles on the official website, offering new game mechanics and ideas from various sources to be play-tested, plus discussions regarding the results of the official monthly surveys, framing him as the friendly face of 5e, despite the rumored drama with other members like Monte Cook behind the scenes. Mearls also seems to have a firm grip on the operation of the Dungeons and Dragons Adventurers' league. Recent changes to the rules had a mixed reception, since many of the changes seemed to double down on what typical players already disliked about organized play. The changes in general seemed aimed at players and DMs who would abuse the league's honor system, as well as dropping in on specific modules only to take story-critical items with them and leave the group. While the changes had honorable intentions, when league players and DMs offered input, Mearls refused to budge on the strictness and tediousness of the new rules.
A few other small restrictions of seeming dislike among players are as follows:
- Fire arm proficiency being impossible to have, despite the clear presence of firearms and smokepowder based weaponry being present in the forgotten realms and enemies who DO have firearm proficiency.
- Smokepowder cannot be used with the intent of being made an explosive for offensive reasons such as a makeshift hand grenade, despite their being mechanics for smokepowder going off if handled too roughly by players or being used as ammo for fire arms.
- Players are unable to take things they find during their adventures outside of the module. They instead achieve progression points for checking off certain goals outlined in adventure modules. They can then spend these progression points on items they have unlocked. You unlock items for purchase by encountering them in-game. There is no longer gold or treasure that your character can just find and keep. Anything you find while playing a module stays within that module unless you purchase it with points. So if you find a chest full of 500 gold and a magic item, congrats you can't actually keep what you find, you get X number of progression points, you can spend after the fact.
On the end of April in 2020, after months of social media silence starting from June, it was revealed on Twitter by Jeremy Crawford that Mearls had been removed from his position as the head of the tabletop development team, was no longer associated with the tabletop development side of things, and hadn't been for a year. The reasons why were initially unclear - whether he was fired or simply transferred to other parts of WotC, such as on the team developing Baldur's Gate III - was unknown. On May 21st 2020, it was confirmed on the official D&D podcast Dragon Talk that "Mike Mearls is back full time on the RPG again" and had been "working on some computer game stuff".