Monster Hunter games are action role-playing games that takes place in a shared low fantasy setting, where the human-like species have a pre-industrial level of technology such as steam power, but continue to study the ruins of a long-past advanced civilization. In the setting's less populated regions, monsters roam the landscape and threaten small villages or research bases that have been established to study the ruins and these monsters. Players take the role of a Hunter that serves to help protect the villages and bases from these monsters, typically aiding in researching these. This is generally presented through a series of quests to slay or trap a monster but can include numerous optional challenges.
The core feature of Monster Hunter is its compulsion loop. Unlike traditional computer role-playing games, a player's Hunter does not grow and has no intrinsic statistics or attributes whatsoever. Rather, the Hunter's abilities are instead defined by the specific weapons and armor selected. The player can equip weapons, armor, and items most beneficial towards completing a given mission, and if successful, the Hunter is awarded in both in-game money ("zenny") and loot representing parts from the monster. These parts, along with other resources collected while on missions or through mission rewards, can be used to forge or upgrade new weapons and armor which then can be used in against more powerful monsters and tackle more difficult missions, completing the compulsion loop. Harder missions are typically restricted by a hunter's rank, which cumulatively increases as the player completes specific missions designated by the quest giver. Mission rewards are often generated randomly, often requiring the player to grind the same monster repeatedly to get the right parts. Weapons and armor have intrinsic bonuses or penalties towards certain types of elemental or physical damages, and may provide special skills which can be fine-tuned through the mix-and-matching of equipment pieces.
The games feature a variety of different weapon classes, ranging from swords, hammers, and bows, with the most recent titles (Generations, World, and Rise) having a total of fourteen classes. Each weapon class has a unique set of combat maneuvers and reflect a number of different play styles based on speed of attack, damage strength, range and the application of buffs and debuffs to monsters and allies. Monster Hunter games use an "animation priority" combat, committing the player to a move until the animation is completed and leaving them potentially vulnerable to a monster's attack. Further, players are encouraged to watch their Hunter's health and stamina. Losing all health will force a retreat to a base camp, and after three such retreats, the mission is deemed a failure. Performing most combat actions consumes stamina, which recovers in a short amount of time; once exhausted of stamina, the Hunter becomes vulnerable as they pause to catch their breath. Monsters and other environmental hazards can also inflict blights and other negative status effects that impair combat abilities. Combat is centered around watching for a monster's tells prior to an attack to be able to dodge it and/or make a counterattack, and looking for openings to unleash strings of attack combos, depending on the Hunter's current weapon. Unlike most other action games, Monster Hunter fights have been compared to a series of boss fights.
Nearly all Monster Hunter games have a single-player mode; in these, the Hunter is often accompanied by a Felyne or Palico, a sentient cat-like creature that provides support and limited offensive abilities in combat. Most Monster Hunter games released with support for four-player cooperative online modes, allowing the group to hunt down stronger versions of monsters, though this support has since been disabled in older games. The games typically have a main quest line, frequently called "Low Rank" or "Village Quests", which can take up to fifty hours to complete. Once completed, the game opens up with new "High Rank" or "Gathering Hall" quests, featuring stronger versions of monsters they have previously faced, as well as new monsters are yet seen and unique variants of these foes, all of which provide better components for more powerful weapons and armor sets, providing hundreds of hours of potential gameplay following the main quest. Most, if not all titles have a third rank of difficulty ("G Rank" or "Master Rank"), released after the base game. These add more monsters, locations, weapons and armour sets to the game.