Two Worlds:
We wanted to acknowledge that there are two general tendencies of using the terms described. One is related to fans that mostly play the games in Japanese (Japanese), while the other one (Western) is related to fans mostly playing these games in English. Both groups differ somewhat in the way they use the terms, with sometimes matching, but sometimes also different meanings. The lexicon describes the ways in their most typical forms for both groups. Often a term will only be used by one group.

Hybrids:
We try to describe the most typical and pure form of a given term. In an example, we can say that game A is a visual novel, and game B is a dating sim. But there is also game C, and it may combine elements of both a VN and a DS. Attempting to cover such hybrid or borderline cases is not really possible. But it may happen in the future that a hybrid form will establish itself as a standalone entity and be given a new name.

Convergence:
It's not impossible that English-speaking communities, while preferring either the Japanese or Western usage will sometimes use the other one's terminology, simply because the communities often interact. The result will probably be a bit confusing, and it can be seen in the articles in Wikipedia, where the terms ren'ai game, bishoujo game, visual novel or BL game and other terms were worked on by members of communities preferring the one or the other usage.

ADV	--none--	- "adventure game" (mostly describing choose your own adventure structure of play)
adventure	Typical usage: Normally, this term is used for games with BG/Sprite/Text gameplay where the text is inside a textbox. These may or may not contain sex and may or may not contain choices. Abbreviated ADV/AVG. Examples: Kanon	---none--- (Western usage associates this word with point-and-click adventures)
ANM	--none--	- "anime game" (mostly describing a linear gameplay with obstacles structure of play, used mostly with Desire, EVE and Chain)
AVG	--none--	- "adventure game" (mostly describing choose your own adventure structure of play) - "adult video game" (mostly describing games that contain sex or adult scenes)
bishoujo game, b-game	Origin: Meaning "pretty girl". Typical usage: Games that include girl-aged (cute) characters, usually aimed at boys around their teen ages. Applicable to bishounen games in the same way. Examples: Kanon	Origin: JAST and PP started to use this term to describe all the games they sold, and all featured sexy anime girls. The term is not limited to girls, but also to women. Applicable to bishounen games in the same way. Typical usage: A game where manga-style pretty girls/women take on a leading and meaningful storywise or visual role within the focus and aim of the title. Examples: Pick Me Honey
boy's love game, BLG, BL game, boys' love game	---none---	Origin: A term describing male-male relation- ships. Typical usage: This term is used by Western fans to describe games dealing with male homosexual relationships targetted at female audience. These may or may not include sex. Examples: Graduation, Kuro No Tsuki
dark game	---none---	Origin: Fans started to use this term to describe games driven by sex and depicting rape. Typical usage: Games featuring non-consensual sex and having low moral standards. Examples: Virgin Roster, Tsuki
dating sim, dating simulation, simulated love game	Origin: Konami's Tokimeki Memorial was the first game to use the term "dating simulation" to describe itself. Typical usage: This term may be used for games where the main objective is to create a relationship with one of its girls. Examples: Tokimeki Memorial	Origin: Adopted Typical usage: Western fans often call all games one can end with a girl dating sims, including ones with BG/Sprite/Text-based gameplay. The more logical way is to describe them as games that focus on dating/picking up girls in a stats/schedule-based gameplay. Examples: Casual Romance Club
digital novel	Typical usage: Sometimes used to refer to doujin works (without branches?).	Origin: A term used in late 1990's to sometimes describe the Fairy Gods series. Typical usage: The term was used for productions with no choices. Examples: Fairy Nights
eroge, ero gemu	Origin: Meaning "erotic games". Typical usage: Games that include sex. In this usage the term is not limited to erotica, but also includes pornography (explicit sex) Examples: Gibo	---none---
gay game	Typical usage: This is an original Japanese term describing games with BxB homosexual relationships targetted at homosexual males. Examples: ...	---none---
girl game, gyaru gemu, gyaruge, galgame, galge	Origin: Meaning games that innvolve girls. It doesn't mean that the games are for girls. Typical usage: A game that focuses on anime girls. Many gameplay styles possible. Examples: Kanon	---none---
girls game	--- see shoujo game ---	--- see shoujo game ---
hentai game, h-game	---none---	Origin: Adopted meaning, the Western fans started to use this term for the games that distribution companies like JAST, PP or GC sold, their common element being usually the inclusion of explicit sex scenes. Typical usage: Used to describe anime-style games with explicit sexual content. Gameplay or visual design is not relevant. Examples: Gibo, Season Of The Sakura
jun'ai game	Origin: Meaning "pure love". Typical usage: Games heavily emphasizing profound feelings of love. Examples: ...	---none---
kichiku	Origin: Meaning "???". Typical usage: The term is used to describe brutal or extremely explicit sex games. Examples: Dystopia	---none---
kinetic novel	Origin: A series of productions by the company Key/Visual Arts, also a website called kineticnovel.jp selling products described as kinetic novels. The flagship project Planetarian had no choices, but no choices isn't a strict rule. Typical usage: The term may be limited to whatever similarities a given work has with works sold at the kineticnovel site and how they are being sold/marketed. Examples: Planetarian	Origin: Adopted term. Typical usage: In 2005, the newly introduced term that the no-choice Planetarian translation brought meant the term "kinetic novel" was adopted to describe productions that have no choices. Examples: Planetarian, Fairy Nights
nakige, naki gemu	Origin: Meaning "crying games". Typical usage: Used to describe games that make one cry. Examples: Kana	---none---
NVL	- "novel" (probably applied to any text-based game, but also to visual novels)	- "digital novel" (used in conjunction with Fairy Nights)
play novel	Origin: Chunsoft's marketing name for their BG/Sprite/Text type of games.	---none---
raising sim, upbringing simulation, stats-raising sim, simulated life game	---none---	Origin: This term was developed to describe games like Graduation or Princess Maker. Typical usage: Describes games where the goal is to manage and take care of characters. Examples: Graduation, Princess Maker 2
ren'ai game	---none---	Origin: Western fans started to call these games "ren'ai" when they had significant romantic content in them, ren'ai meaning romantic love. Also, the term is also being used to distinguish such games from story-free sex-oriented productions. Typical usage: Currently, it is used to describe a game where the romantic element plays the dominant part. Examples: Hourglass Of Summer
shoujo game, shoujoge, girls game	Typical usage: This term is used for games targetted at females. Relationships may be homosexual or heterosexual, the protagonist may be male or female. This is a very global category. Examples: Amgine Park, Kuro No Tsuki	---none---
shounen-ai game	---none---	Origin: A term describing male-male relationships in general in English. The game terminology usage is somewhat different. Typical usage: This is used by Western fans to describe BxB (Boy's Love) games targetted at female audience that do not include sex. Still, this can also be used to describe any game with BxB relationships. Examples: Graduation
sim date, sim date RPG	---none---	Origin: Forkheads' Flash game "Love Hina Sim Date RPG" introduced this term. Before that though, the game "SimGirls" probably established the base for the usage. Typical usage: Used for typically Flash-based games that use collecting and attributes to win girls or images of them, without having a significant story. Examples: Love Hina Sim Date RPG
SLG	--none--	- "simulation game" - "simulated love game" - "simulated life game"
sound novel	Origin: A series of games by Chunsoft was given this name. Typical usage: Typically, this term is used for games that feature a more photographic and realistic visual side in a BG/Sprite/text based gameplay. But photographs aren't requirement, and the game may be completely drawn - but also use real people as characters. Examples: ...	---none---
utsuge	Origin: Meaning "depressive game". Typical usage: Used to describe games that have a depressive effect on their players. Dealing with death and similar. Examples: Kana	---none---
visual novel	Origin: Leaf's game Shizuku was the first game to be called "visual novel" by their makers. Typical usage: Normally, this term is used for games with long text and quality story, where the text is overlayed directly (and is not inside a textbox). These may or may not contain sex and may or may not contain choices. Examples: Shizuku	Origin: Adopted term. Typical usage: A visual novel is any game that involves a background +sprite +text gameplay. If not used to describe the game mechanic, the term can also emphasize the aspect of story ("good" story, less hentai etc...) Examples: Gibo,
yaoi game	---none---	Origin: Western fans started using this term for all games with BxB relationships that contained sex. Typical usage: Any game dealing with BxB homosexual relationships, regardless of whether it includes sex. Examples: Kuro No Tsuki
yaruge, yarugee, yarige, yarigee, yaru gemu, yari gemu	Origin: Meaning "doing-it games", equivalent to "mindless sex". Typical usage: Used to describe games which highly emphasize the sex element while neglecting story. Examples: Gibo	---none---
yuri game	---none---	---none---

• D I V I D I N G     G A M E S
  Here, we have a pool of games that we want to divide into parts. With these methods there will be no games in the pool left.
• by gameplay
• dating sims
andvisual novelsandRPGs, shooters etc,...
• ...more divisions: by length (long/short)...
• by content
• bishoujo/bishounen
or
• ren'ai/non-ren'ai
or
• BxG/BxB/GxG/GxB
or
• general/girl's/boy's
or
• hentai/ecchi
or

• by production
• professional/semi-pro/fan-made
or
• ...more divisions: by commerciality (commercial/freeware)...
• G R O U P I N G     G A M E S
  Here we do not divide, but we pick games from the pool that have specific characteristics. All other games are left in the pool.
• by a common element
• maid training, depressive, harem games,...

This method of dividing game takes into account the dominant game mechanic of the given title. For the Western usage, this is the most important division type.

• 1. Number-based gameplay
• dating sim (DS)

The gameplay of dating sims uses player attributes and/or schedules and task management as means to move forward the story and relationships of the player and the courtable characters.
Examples: Casual Romance Club, True Love...

 

• sim date, sim RPG

These games do not have a story, ...
Examples: Love Hina Sim Date

 

 

• raising sim (simulated life game, SLG)

In these games you usually take care of a person or more, attend to their needs, so that their statistics go up.
Examples: Princess Maker 2, Graduation II,...

 

 

• 2. Text-based gameplay

• visual novel CYOA (ADV)

These may be best described as interactive books (fiction), or choosing your own adventure. They will differ in the amount of text to read as well as the number of choices and their true relevance for the story.
Examples: Kana, Kango Shicyauzo, Season of the Sakura,...

 

• visual novel adventure (ANM)

Some VNs will have just one ending, but make it an little more difficult to achieve and prolong gameplay by having the player first exhaust certain text/talk options before letting the story advance. Often these games can be seen from the perspective of more than just one of the story protagonists. There will be no courtable characters because of this linearity.
Examples: ADAM, Desire, Chain,...
• cinematic visual novel (kinetic novel, digital novel, NVL, KN)

A visual novel with no choices or path branches and without any gameplay advancing obstacles.
Examples: Fairy Nights, Until We Meet Again...

 

 

• 3. Other types of gameplay

These games may in theory have any type of gameplay, usually they will use the pretty anime girls as bonus for achievements in the game's main gameplay.
Examples: Knights of Xentar (RPG), Sentimental Shooting (shooter), Metal & Lace (fighting), but also hybrids like DS/RPG,...

     

Below are some examples of categorizing games by their content:

• Character focus
• bishoujo (bishojo game, b-game)

A game where manga-style pretty girls/women take on a leading and meaningful storywise or visual role within the focus and aim of the title.
Examples: Virgin Roster, Sentimental Shooting, Season of the Sakura...

 

• bishounen (bishonen)

A game where manga-style pretty boys/men take on a leading and meaningful storywise or visual role within the focus and aim of the title.
Examples: Amgine Park

 

• Romance level
• ren'ai (renai, romantic love)

A game with romantic relationship development as its main focus.
Examples: Hourglass of Summer, Crescendo,...

 

 

• light games (semi-ren'ai)

A game with some relationship development where love is a supporting element.
Examples: Do you like horny bunnies? 2, Slave Pageant,...

 

 

• Sexual content level

• hentai (hentai game, h-game, sex game, eroge, erogee, ero-gemu)

A game with explicit sexual content (the Western meaning of hentai).
Examples: Gibo, Pick Me Honey, Critical Point...

 

• ecchi (erotic game)

A game with mild erotic content (lingerie) or light sexual undertone. Normally non-h means anything under the adult rating.
Examples: Eve Burst Error, Amusement Park,...

 

• Orientation

• BxG

Protagonist is male, pursuing females.
Examples: Pick Me Honey...

 

 

• BxB (Yaoi game)

Protagonist is male, pursuing males.
Examples: Kuro No Tsuki,...

 

 

• GxB

Protagonist is female, pursuing males.
Examples: Amgine Park,...

 

 

• GxG

Protagonist is female, pursuing females.
Examples: Midsummer Day's Resonance

 

 

• Audience

• Girl's games

A game targetted at girls.
Examples: Amgine Park
• BL Game (Boys' Love, Boy's Love)

Protagonist is male, pursuing males. The game is specifically targetted at female players.
Examples: Kuro No Tsuki,...

 

• Boy's Games

A game targetted at boys.
Examples: Gibo

Below are some examples of categorizing games by their production:

• Creation group rating

Please note that this has nothing to do with the quality of the work itself.
• professional (pro)

A team that developed the game was made of experienced creators doing their main full-time jobs.
Examples: Hourglass of Summer, Crescendo,...

 

 

• semi-pro (commerical doujin)

Usually small businesses selling their games for below-full prices.
Examples: Summer Schoolgirls

 

 

• amateur (doujin)

A game made by people with no experience with the industry.
Examples: Amgine Park

 

 

This method of dividing games is based on common usage of terms and generalizing a certain aspect of the game (e.g. tear-jerkers - games that make you cry). It's the theme of a game and it groups titles related by something other than a strictly systematic aspect. Often the names will be self-explanatory, so we'll limit ourselves to a few examples. Most often, they will relate to sexual preferences.

• by common element
• harem game

A game where there are many girls that are open for one protagonist.
Examples: Pick Me Honey

 

 

• slave/maid trainig

Games that involve the mentioned sexual practices.
Examples: Slave Pageant, Maid's Story...