Yes, half-elves are usually medium in size in Dungeons and Dragons, the popular role-playing game. They're typically portrayed as possessing a blend of human and elven physical characteristics, such as pointed ears, slender build, and elven features. However, their exact size and other physical attributes may vary depending on the edition of the game you're playing and the specific world setting in which they exist. So while half-elves are often described as medium in size, it's important to note that there can be variations and exceptions to this rule.