Easily the biggest influence on how I've run tabletop RPG campaigns over the last few years has been the OSR movement. Short for Old School Renaissance (or Old School Revival, depending on who you ask), it's a subgenre of games that look back on the origins of D&D and bring forward ideas that had become unpopular in the modern hobby—such as lethal dungeons, morally grey heroes, and an emphasis on player problem-solving over stats and rolls.
Apparently it's also been a big influence on the best game of the year so far, Mewgenics—with one specific element having inspired two of the game's most memorable areas.
