RPG is a broad term, encompassing many different forms from turn-based RPGs like Pokemon, to RPG Shooters like Borderlands, There is really no way to define an RPG. Traditional RPGs however, do feature some common features:
Menu Based Combat System.
Levels and Experience.
Skill points that the player can invest as they choose.
Main Quest line with side quests for extra rewards.
Abilities to change how you interact with the game world e.g. lockpicking or hacking.
An RPG, or Roleplaying game, is a game that is built around immersing the player in the game world. The player can build their character to fit their own style of play. These games are rapidly growing in popularity and span over multiple subgenres. Player immersion is becoming more and more important as a selling point of most modern games. This means that many games at least feature RPG Elements. RPGs are meant to take the player on an adventure through a new world.
There are many fantastic RPG games, here are just a few examples of noteworthy RPGs:
Final Fantasy
Stardew Valley
Terraria
Fallout
Borderlands
Destiny
Cyberpunk
Pokemon
Castle Crashers
Smile For Me
RPGS can challenge the players in many different ways, and the difficulty of these activities will usually be influenced by the player's level or section of the game. Examples of common challenges are:
Combat Challenges
Puzzles
Fetch Quests
Bosses
Level caps
Mazes
RPGs can reward the player both in the short term and long term. For example, after a combat section, the player will earn some exp. This is a small reward however it eventually leads to the player leveling up, increasing their stats and often providing another reward of a skill point that they can then dedicate elsewhere. Examples of RPG rewards include:
Exp
Levels
Skill Points
Weapons
Armour
New abilities
The player will progress by completing missions or quests. These will progress the player through the narrative or story. The player themselves can also progress via level ups, allowing them to become stronger and apply skill points into their character. This is what is known as character progression, and it's a driving force within most RPG games.
RPGs focus heavily on player progression and immersion, this means that it is very hard to come by a linear RPG. The majority of RPGS are Non-Linear as the player can choose how they progress.
Emergent Gameplay elements are very common in RPGs as they provide a deeper level of player choice. One example of an RPG that features heavily with emergent gameplay elements is Legend of Zelda, Breath of the Wild. This game allows you to wake up, turn around and go to fight the final boss before doing anything else (if you think you're up for it). They can choose to progress entirely how they please.
Types of Gamer:
RPGs can appeal to all gamers as they can provide a rich story that all players can enjoy, however, RPGs can be particularly attractive to completionists and hardcore gamers. These games often feature lots of items for the player to collect, as well as side-missions and optional dungeons to challenge the player, often rewarding the player with items that can be used in game, or simply for bragging rites among friends
Age:
Due to RPGs often including online multiplayer as well as themes of horror or violence, they are often rated 12 or above, depending on the level of violence or horror present, this age rating can dramatically increase.
Gender:
RPGs can be enjoyed by all genders, however many hybrid RPGs such as Shooter RPGs, are more popular among men. Some suggest that men enjoy the collection and competition aspects of RPGs more than the story.