If you watch a full Let's Play of a video game, are YOU less likely to buy the game?

[Dub-Z]

I don't watch anything I haven't already played. Even scenario, context, story beats and discovery of the gameplay systems is spoilers for me, in what I get out of games. There's rare exceptions where I might watch the one streamer I tune into play a last gen game I put off for way too long, but even then I'm only half paying attention and just there to hang out, maybe listen while I play something else.

I would say it'd definitely lead to me feeling like I don't need to play something, and skip it or put off buying it until it's way cheap and I've hopefully forgotten some of it. I do remember catching a hefty stream of Outlast when it was new. I tried to play it three years later, the thrill was gone, I still knew what to expect, and I didn't get very far before throwing it on the backlog.

[JackofTears]

Depends on the game, yeah? "Doki Doki Literature Club" and "Walking Dead" are essentially visual novels, so there isn't really a kind of satisfaction unique to yourself that comes from gameplay. You don't have to feel and learn the controls the way you would in an action game, you don't have the freedom to explore in different directions that you'd have in an rpg, you follow a pretty linear story toward a scripted ending. Mind you, those games do offer you some variety in dialogue choices, but they don't change the game too much in either of those titles. In some visual novels, however, pursuing one girl over another is going to give you a very different experience - consider "Yume Miru Kusuri" where one of the girls is a drug addict and another turns out to be an attempted murderer - and that gives the game replayability. In those cases you're either forced to only understand the game as the Let's Player chooses, or you must watch multiple playthroughs in order to get the full experience.

In fact, that's an issue with any Let's Play: you are forced to experience the game the way the player wants. I have a harder time watching an LP after I've played a game, than before. If I'm watching a game before I play it (only if I'm making up my mind), then I'll stop watching the moment I've made my decision. If I make it to the end of the series without making a decision, it's likely I won't be buying the game. If I am on the fence and the gameplay video convinces me this is a game I want, then I will stop watching and buy the game - maybe coming back if I find myself at a hard puzzle. If I have already played a game, I see every flaw in the LP's choices and it frustrates me when they make stupid mistakes or miss obvious clues.

Part of the fun, in playing a game, is the experience of working through the mechanics and the thought processes which bring you to make the decisions you do. It's easy to watch a playthrough of "Witcher 3", for example, and engage in the LPer's story, but it is a far different thing to feel the pressure of certain important decisions and mull over the decision and its consequences - which feel much more personal when you play the game. When you find Ciri with the X's (spoiler avoided), for example, the emotion of that scene will only truly be felt when you have spent the last 60 hours or more in the shoes of Geralt; and when you have to make that final decision at the end of the game ... watching that on Youtube is not going to be nearly as powerful an experience as when you must make that decision for yourself.

But if it's a game I never intend to play, then I have no problem watching it and maybe, if I really enjoy what I see, the gameplay will change my mind.