Editing Dungeons & Dragons 5th Edition (section)

== Combat ==
Combat is faster. The advantage/disadvantage mechanic speeds up combat by making situational modifiers simpler, and the Monster Manual offers the option to let monsters deal set damage per attack instead of rolling every time.

There's a "disengage" maneuver that lets you step away from an enemy without provoking an AoO. The "charge" maneuver is noticeably missing , but you can both move your speed and do all of your iterative attacks (which are now a class feature and not based on your to-hit roll.) In addition, you can now break up your movement over the course of your turn; do a partial move, action, then more moving instead of "move then attack." Two weapon fighting doesn't give you a huge minus to your attacks, you just need to use two light weapons, spend your bonus action for the round, and you don't get your usual attribute bonuses with the off-hand.

Resistance, vulnerability and immunity are simplified. Whereas before they used a numeric system, it's now a Pokemon-style double-damage/half-damage/no damage system. Also, any of these matters is applied explicitly after any circumstances in a mathematical order of operations - example given in the PHB is a character with Acid Resistance being hit for 25 Acid damage whilst under a spell that lowers damage by five, so the initial 25 damage is lowered by the spell first, then resistance gets applied, so only 10 Acid damage is inflicted.  Also, the number of monsters with innate damage vulnerabilities is much lower, but there are also fewer things like Spell Resistance to allow monsters to just nope the hell out of the way during magic attacks.

Creatures and characters now have a set move speed per turn, instead of a move action, allowing them to split up their movement however they wish throughout their turn, including between attacks. Because moving is no longer a single action, the "five foot shift" maneuver is no longer present.

Special "legendary monsters", such as [[dragon]]s or [[aboleth]]s, can perform a  "legendary action" at the end of another character's turn, and may also use the ambient magic within their lairs to perform unique attacks. They can do this a set times per round, usually three. They can also affect their surroundings indirectly simply by existing, using “Lair Actions.”  Finally, there are the "Regional Actions," which allow monsters so imbued with magic that they can modify reality itself a little to do just that, like adding swarms of choking flies around demon lairs, or helping good-hearted people find paths in confusing mountain passes for Gold Dragons.  A monster that has Legendary, Lair, and Regional Actions has special rules for doing all of them in a single initiative order, usually doing automatic Lair and optional Regional Actions on Initiative 20.