Intro to Pacifist Run "Prospect" Posts & Game Lists

Before getting our own pacifist run posts started, we decided to make some one-off posts mentioning potentially promising pacifist run "prospects" we'd heard about. Some are games we played ourselves, while others are known or at least rumored to be winnable using largely non-violent strategies...
Two Worlds I 
Ideally we'd have played and completed pacifist challenge runs through 100% of the prospects covered, but since we only have a few volunteer contributors,  there probably won't be time for us to play all the best pacifist run prospects for years. (That's particularly true of  the CRPGs, which often take dozens of hours to complete, and often even longer when using challenging non-violent tactics that the original game designers might not even have intended for players to use to win.)  Also, many of the newer top prospects for zero-kill runs also demand higher-powered CPU's than we have available at the moment, or else are only available on consoles that we don't own yet (like the PS3 or PS4). 
Razor-sharp instincts (honed like tempered steel on the frontlines) tell us we'll need a PS3 before we can take this mission on...
So we've started working on putting together some game lists to identify prospective pacifist-run prospects, with the help of many other gamers who have compiled their own partial lists, or written posts in various places about games that can be won via pacifist challenge or "zero-kill run."
Atrus from Myst, working hard on finish a writing project...
First up will be the Zero-kill Run Games List: A game where players are given the option to use violence to win the game, but which is also capable of being completed with literally zero kills. "Zero Kill Run Games" may be of interest to scrupulous pacifist players unwilling to kill a single living entity, yet who aren't intimidated by dangerous in-game environments— and who also like the idea of spending hours running away from hostile enemies, sneaking around in the shadows, quaffing invisibility potions, or trying to use talk, non-lethal spells, or various other creative nonviolent methods to stay alive.
Eschalon Book II, a CRPG that can be won as a zero kill run. Not only can it be completed as a perfect zero kill run, it can also be won without inflicting a single point of damage on any foe— while still allowing the player to accumulate an enviable fortune in gold, gemstones, and other treasures removed from the enemies' possession...
The second category, the "Pacifist Challenge Run" game list, will include at least two subcategories:

Mainly, it will include games that "almost" achieve the zero kill run standard— yet fall short in just a few unavoidable places, due to the game's programming and design. (Sometimes we've seen others refer to such games using the term "minimum kill run games.")
Two Worlds I is one of our favorite "pacifist challenge run" games, in which the vast majority of the game can be completed nonviolently, despite the presence of a few unavoidable instances where a few foes must be dispatched in order to continue.
There are many versatile games in which the player can creatively avoid killing hundreds of in-game "enemies" for dozens of hours— yet somewhere before completion of the game, the game's design forces the player to choose whether to either quit playing altogether, or be forced to compromise and dispatch as few as 1 or 2 foes in order to continue. (Some common scenarios where this happens include a scripted plot event where the game requires a key villain to be dispensed with before there is any way to continue with the game's plot, or a sealed door that is programmed to remain unopenable unless a specific in-game entity gets dispatched first.)
Eschalon Book I (unlike it's two fully zero kill run-enabled sequels) is a good example of the situation described above: It allows the player to get more than halfway through the game using a wide array of purely non-lethal strategies. However, once one reaches a certain wizard tower, the player must choose whether to dispatch a few foes to continue, in order to open sealed doors that cannot be opened in any other way.
This situation is common in otherwise-versatile stealth games, RPGs, and also many platform games, in which the game design allows the player to avoid kills throughout the vast majority of the game, yet still disqualifies the game from being a zero kill run by forcing players to dispatch one or more "bosses."
Trip World (released in 1992 for the original Nintendo Gameboy) is an example of a game in which a pacifist challenge enables the player to avoid dispatching a single enemy using various creative strategies (such as transforming into "Flight Yacopu," as seen at left)— with the exception of the game's bosses, who cannot be bypassed without administering a number of stout kicks (as seen at right) to eventually knock them off the screen.
Even if these games don't qualify as strict zero kill runs, many of the "Pacifist Challenge Run" games will obviously still be of interest to many of us who like to attempt a zero kill run in every game we play, yet still want to still continue playing after hitting an insurmountable obstacle to achieving the zero kill standard: After all, these "imperfect" pacifist run games often still provide potential for dozens of hours of creative gameplay with no violence or killing...
The Fallout series (shown above via the screenshot from Fallout 4) and Deus Ex series (not shown here) are two examples of violent game franchises that have nonetheless gained attention for giving players impressive freedom to eliminate or minimize kills...
The second subcategory of the "Pacifist Challenge Run" list are simply unconfirmed prospects that show some strong promise for a zero kill or pacifist challenge run, but which haven't been decisively tested yet: This is usually because we either can't find a single instance of anyone mentioning an attempt to do a pacifist challenge run in that particular game at all (e.g., Gothic 3, to name just one prospect that comes to mind), or because we've seen conflicting assertions about what is/isn't possible in a particular game. (The latter problem sometimes occurs when a game is mentioned on a game forum, and contributors who don't like pacifist-run gaming chime in to state that it's impossible to win without violence/killing, while others contribute follow-up posts to disagree ...)
Even after research, we could not settle the question of whether 'Vampire the Masquerade: Bloodlines' was a zero kill run or just a noteworthy pacifist challenge RPG, so will have to find out for ourselves...

The Nonviolent Games List

Last but not least: The very broad "Nonviolent Games" category, featuring a selection of the huge array of games in which the gameplay is inherently nonviolent.
Flower is a game for the PS, PS4 and other platforms, in which players enter the dreams of flowers and control the wind to push flower petals through the air, enabling them to bring new life and changes to the in-game world— but not to kill anything, as there are no in-game enemies.
Happily for non-violent souls desirous of doing some serious gaming, there are so many nonviolent games we could never list them all, and lots more of them are still being made on a regular basis (particularly in the casual genres of games where nonstop action isn't always the mode).
Myst is an example of a classic game in which no element of the gameplay involves violence, although it still features some dark and macabre themes in the game's plot.
Players interested in finding an absorbing game that doesn't have any violence built into the gameplay at all might find good prospects listed somewhere in the "Nonviolent Games" category— but with the caveat that many nonviolent games (i.e. games that don't give the player the option to solve objectives using violence) still feature disturbing imagery, horror or suspense themes, or unavoidable deaths of particular characters scripted into linear plotlines.