Marvel's new Dawn of X reboot has given the X-Men a specialized team for every occasion. The most magical of these is Excalibur, a group that deals with magical objects and threats. Excalibur was originally formed to help the new Captain Britain in her duties to protect Britain and its magical alternate dimension Otherworld, but so far its true purpose has been to help Apocalypse achieve his ultimate goals as a mage. In the process, almost every character on the team has developed as a result of their exposure to the magical side of Britain. There's a common thread, too: they're taking levels in classes from Dungeons and Dragons.
D&D's Fifth Edition launched in 2014, paring back the endless options of classes and powers in previous editions to a handful of iconic roles. Some rely on physical strength and combat prowess, while others are geared toward unleashing inner magical strength, specializing in certain skills, or healing and support. Looking at the Excalibur team through the lens of the most popular fantasy role-playing game, the group suddenly becomes an iconic D&D adventuring party: a warrior, a magic-user, a thief, a healer, and a bard.
The team also includes a battlefield-controlling secondary caster to round the party out. This is a subtle but thematically appropriate high concept for a superhero team, but as we've seen recently, series writer Tini Howard is a fan of gaming. Apocalypse, as mentioned above, has become focused on casting spells and learning about ancient magic. His focus on learning rituals and recording them in arcane tomes fits the Wizard class perfectly. Wizards in D&D Fifth Edition use practiced spellcasting as recorded in their spellbook. Apocalypse best fits the Lore Mastery wizard school, a class from D&D's Unearthed Arcana playtest content. Apocalypse has also spent eons focusing on his inherent abilities, which means he already had numerous levels as a sorcerer, a class that uses spontaneous spellcasting derived from inborn magic. (He's a Celestial bloodline sorcerer, but that means something very different in the Marvel universe than in D&D and Pathfinder.)
Meanwhile, Betsy Braddock has taken on a new class as well. The psychic mutant was previously Psylocke, who used the Psion and Ninja classes from earlier editions. But now that the X-Men have relaunched, the Braddock heir has taken on her brother's old mantle as Captain Britain, switching out her Ninja levels for Paladin. Paladins are knights devoted to a cause, combining martial prowess with magic derived from an oath they've taken. Captain Britain is specifically an Oath of the Crown paladin, a subclass who upholds a nation's traditions and protects and bolsters their allies. Her devotion to both Britain and Krakoa are cause for conflict, but also drive her.
Rictor, in contrast, has focused entirely on his inborn ability to control earth but has recently discovered a connection to an ancient society that has changed him greatly. Rictor has been welcomed into the fold of a circle of Marvel druids who believe that his mutant abilities are the same nature magic that they have used for centuries. Druids in D&D work similarly, drawing power from the natural world to control the elements. If Rictor were a Fifth Edition character, he would follow the Circle of the Land, who focus on the terrain to empower their spellcasting.
Rogue has little in common with her namesake class. She "steals" powers from those she touches, but stealing magical ability is beyond the scope of the 5e rogue. In the newest issue, Excalibur #9, she nicks the ability that warwolves have to dissolve their prey, leaving only a skin behind, and then wear it to disguise themselves as their victims. In other words, Excalibur's Rogue combines her super strength and increased mobility with wearing the skins of beasts and temporarily assuming their supernatural abilities. That means the closest analog is actually Totem Warrior Barbarian, a class focused on power, durability, and temporary bursts of superhuman might. Totem Warriors choose a real or mythical beast and then draw power from it. Rogue's totem, in this case, is whoever she most recently threw hands with.
This leaves Gambit and Jubilee, two characters who have received little growth so far as the various plot threads of Excalibur unfurl. These two don't necessarily need to develop D&D class levels because they already have them. Gambit has been a Rogue of the Arcane Trickster variety for his whole career. Jubilee uses light and sound in her attacks, typically to distract enemies rather than damaging them outright. This makes her most like a Bard, although admittedly a low-level one. Maybe Jubes just doesn't feel a need to gain levels since her son just became a monster with Challenge Rating 17.
So far it's been the New Mutants embracing RPG combat, but we wouldn't be surprised if Excalibur follows close behind.