According to the FAQ, it's possible using Idle Master. I've never attempted it so I can't verify if this actually works.
https://psteamcommunity.yuanyoumao.com/groups/idlemastery/discussions/0/615085406651320102/

Can Idle Master be used to pad my playtime of a particular game?

The steam-idle.exe application that's included with Idle Master can be given a command line argument of the appid of the game you'd like to idle. For example, if you'd like to idle Team Fortress 2 for playtime, you can simply run "steam-idle.exe 440" from a command prompt. There is no user interface for this, it must be done through the command line.

引用自 Glimmer：

According to the FAQ, it's possible using Idle Master. I've never attempted it so I can't verify if this actually works.
https://psteamcommunity.yuanyoumao.com/groups/idlemastery/discussions/0/615085406651320102/

Can Idle Master be used to pad my playtime of a particular game?

The steam-idle.exe application that's included with Idle Master can be given a command line argument of the appid of the game you'd like to idle. For example, if you'd like to idle Team Fortress 2 for playtime, you can simply run "steam-idle.exe 440" from a command prompt. There is no user interface for this, it must be done through the command line.

Thanks :)

Create *.txt file in IM folder, fill it with

start "" "steam-idle.exe" appid

, put a correct appid, rename the file into *.bat and run.
????? Profit!
You can also put several lines if you want to idle several games in the same time.

引用自 М'аiq thе Lаzу：

Create *.txt file in IM folder, fill it with

start "" "steam-idle.exe" appid

, put a correct appid, rename the file into *.bat and run.
????? Profit!
You can also put several lines if you want to idle several games in the same time.

Thank you! Does it need to be name a certain name (txt file)

I'm just curious, is there any time when padding your game hours is beneficial?

I'm not familiar with any Steam/Valve reason. Play time has no impact on booster packs other than playtime being the requirement to receive cards and receiving all your free cards being the requirement for booster pack eligibility.

I vaguely recall some achievements that require total amount of time. Some giveaways run by 3rd parties may care about playtime. (E.G. Company X makes a sequel and accounts with 300+ hours in the first game are eligible for a promotional giveaway)

I think people generally want to artificially increase their play time so that their Steam reviews look more legitimate or that (in the case of games like Team Fortress, Counter Strike, and Dota) people generally consider those with higher playtimes in those games to be more trustworthy traders. But because it's so easy to fake, people really shouldn't.

I, for one, idle my steam playtime only for games I've played before I got steam (pretty long process, btw).

The reason I wanted to pad playtime is because of achivements. Also when I play a game I pad another so I get two things done.

Cool thanks for all the comments. Interesting to understand the different reasonings.

Nice thread, but I have a question: where is the IM folder?

引用自 - M4n0L0 -：

Nice thread, but I have a question: where is the IM folder?

Just search steam-idle.exe and and rick-click it and view in its "original folder"

引用自 jshackles：

I think people generally want to artificially increase their play time so that their Steam reviews look more legitimate or that (in the case of games like Team Fortress, Counter Strike, and Dota) people generally consider those with higher playtimes in those games to be more trustworthy traders. But because it's so easy to fake, people really shouldn't.

Dear Admin,

I dont know what a command prompt is. Can you explain a bit how idling finished games work?
Somoene said TF2 is 440, but what are the other games' numbers? And how to find out what number I have to write in the ''command prompt'' which I cant find :D

Sincerely

A fan of Idle Master

引用自 Unforseen_consequences：

引用自 jshackles：

I think people generally want to artificially increase their play time so that their Steam reviews look more legitimate or that (in the case of games like Team Fortress, Counter Strike, and Dota) people generally consider those with higher playtimes in those games to be more trustworthy traders. But because it's so easy to fake, people really shouldn't.

Dear Admin,

I dont know what a command prompt is. Can you explain a bit how idling finished games work?
Somoene said TF2 is 440, but what are the other games' numbers? And how to find out what number I have to write in the ''command prompt'' which I cant find :D

Sincerely

A fan of Idle Master

引用自 Unforseen_consequences：

I dont know what a command prompt is.

http://windows.microsoft.com/en-us/windows/command-prompt-faq#1TC=windows-8

引用自 Unforseen_consequences：

Somoene said TF2 is 440, but what are the other games' numbers? And how to find out what number I have to write in the ''command prompt'' which I cant find :D

There are a few places, the store page and Badges page would be among the easiest to pull up.
TF2:
AppID: 440
Store: http://psteamproxy.yuanyoumao.com/app/440/
Badges: http://psteamcommunity.yuanyoumao.com/my/gamecards/440/

Portal 2:
AppID:620
Store: http://psteamproxy.yuanyoumao.com/app/620/
Badges: http://psteamcommunity.yuanyoumao.com/my/gamecards/620/