Is it Cheating?

Recently I have been involved in some games in which I believe my opponent has been using a computer to decide their moves.  To me this seems like cheating, but at the same time it got me to wondering how different using a computer is from using a book to help in the opening or the end game.  

For playing online chess (when you have days per move instead of minutes) is it acceptable practice to use books?

Is it acceptable to use Explorer or other opening apps?  

Is it acceptable to use a computer?

Is there a way to know for sure if the other person is using a computer?

If you believe someone is using a computer do you do anything about it?

Game explorer and referencing books are ok. The difference seems to be when one player goes away from "book" moves, and the other makes perfect moves in response.

If you suspect a member submit a ticket here: http://support.chess.com/Tickets/Submit

To me none of that is ok, when you're playing a match no matter the length of time involved it should be your mind against your opponents's and nothing more.

Well, correspondence is different.

Haha! I think a lot of people probably do cheat in online chess, but I have played in live in-person blitz tournaments and seen people play extremely well, quickly. So I think it's probable you lost a lot of games because they're just better than you at it? No offense! It is why I never play blitz games online; I'm just not good at playing that quickly! Hell, I'm not very good at playing slowly, either. Haha!

Using an engine is never okay.  The rules allow you to use a book for correspondence chess.  Personally, I don't have time to consult a reference.  Given that I have a job and other responsibilities, it is rare that I ever have more than 30 minutes in a day to play/think about chess.  Many days, I have exactly zero minutes.  Most of the time, I'm rushing to log in to avoid timing out on my tournament matches, which typically only allow 2 or 3 days between moves.  Half the time, I will have only 5-10 minutes to move in 12 games.  I end up just making the first logical looking move that pops into my mind, and moving to the next game.  I couldn't possibly spend the time to actually look up the line to figure out the optimal move in that position.  Of course, that's just me.

This is just my opinion, if they're not somewhere in the 2000+ rated range, I wouldn't worry about cheating. If a player is lower than that and actually cheating, I'd say they're not very good at it, or they need a better computer. lol! Either way, anyone below expert level is still making minor tactical errors. I assume you can send blitz games in for analysis as well? If so, send one of the games in to chess.com for analysis. You will probably be surprised how many tactical errors you and your opponent make that you thought were originally good moves. At least that's what I've found in my games from analysis.

Until we come up with mind-wiping technology that removes all accumulated chess knowledge and training between each game, I think you're out of luck.

Is it considered cheating if you set up the same scenario on your home chess-set (no book or computer involved) based on the online game you are playing & use that to work out possible attacks & counter-attacks??

These questions come up frequently on sites such as chess.com. I have summarized the rules of several of these sites in this article: http://chessskill.blogspot.com/2011/03/databases-and-their-discontents_28.html

Here's an excerpt:

The Rules

In correspondence chess, help is openly encouraged and forbidden depending on the venue and the nature of the help. Some chess organizations conclude that help from books, databases, and even engines is undetectable and make no efforts to prevent assistance. Others distinguish between allowable help and banned: most often books and databases are permitted, but engine use is not.

The United States Chess Federation rules are typical:

You may consult chess books and periodicals but not other players. You cannot use a computer or computer program (chessplaying algorithms) to evaluate a game, but you may use computers for record keeping and databases.
"Your Responsibilities as a Player,"http://main.uschess.org/content/view/7521/393/

Countless hours might be spent gathering evidence against suspected violators so they might be disciplined.

In the past ten years a growing number of chess sites have added another dimension. Correspondence chess games are much faster, there is less record keeping, and far less expense. Moreover, thousands of players who never mailed a postcard are engaged as adversaries. These chess sites have offered a new vocabulary to describe an old practice: turn-based chess, online correspondence, correspondence-style, online chess, net-chess.

The terms and conditions of these sites explain acceptable and unacceptable help:

"Immoral and unfair External assistance"
1) Using computer engines to generate your moves
2) Getting someone else (who may be much stronger) to play ones moves
3) Getting your opponent to artificially resign by pre-agreement

"Moral and fair External assistance"
It is however acceptable and encouraged to use conventional resources which are in the spirit of correspondence chess, such as referencing Opening books (which could be electronic), etc. The use of such resources is considered "research" which has always been an attraction of correspondence chess.
"ChessWorld Terms and Conditions,"http://www.chessworld.net/chessclubs/termsandconditions.asp

The sort of databases that are permitted is specified in some cases:

While a game is in progress you may not refer to chess engines, chess computers or be assisted by a third party. Endgame tablebases may not be consulted during play but you may reference books, databases consisting of previously played games between human players, and other pre-existing research materials.
"Red Hot Pawn Terms of Service,"http://www.redhotpawn.com/myhome/termsofservice.php

Fritz's infamous rook lift against Vladimir Kramnik must be excised from the database if a player intends to use that collection of games for help during play, and massive databases of games from the Playchess engine room are clearly out of the question. In a forum post on Chess.com, Gonnosuke took issue with the distinction made in RHP's TOS, but in reference to something similar at Chess.com:

If you're going to argue against databases, I think you should be arguing against all databases. To allow some but not others is extremely inconsistent when, for all intents and purposes, there's no difference between looking at a high level GM game and an engine game.
Gonnosuke, "Databases -- What is Allowed?"http://www.chess.com/forum/view/community/databases---what-is-allowed?

Chess.com recognizes opening databases as allowable computer assistance.

You can NEVER use chess programs (Chessmaster, Fritz, etc) to analyze current ongoing games unless specifically permitted (such as a computer tournament, etc). The only type of computer assistance allowed is games databases for opening lines in Turn-based Chess and Vote Chess. You cannot receive ANY outside assistance on Live Chess games.
"Chess.com Terms of Service,"http://www.chess.com/legal.html#termsofservice

These sites offering web based chess at correspondence time controls have not only brought in minions of newbies, they host chess forums where players and other interested chess scholars can debate whether databases should be used, how they might be used effectively, and whether such online play resembles correspondence chess or something entirely different. Many of these debates begin with a question posed by someone who neglected to peruse the terms of membership prior to registration.

        Could I clear something up, please? What is the difference between using a database and an engine? I'm not being sarcastic, I genuinely don't know.

Thank you both for your answers - seems my attempts of viewing my online game in 3D shouldn't disqualify me, not that any of it has helped my rankings...     HaHa!

A database stores and searches *old* information from published chess games analysis.  An engine examines and evaluates new positions to generate *new* information.

There is no way to prevent uninformed accusations. Informed accusations are not often expressed. Rather, a suspicious player will be investigated and reported, leading to a ban if the site administrators find the evidence they need.

You will not be banned for following databases in correspondence chess. You could be if you use these resources in live chess.

I think you give the admins too much credit tbh, the reason most correspondance organisations dont actually legislate for it is the damaging and hurtful nature of being accused 

The only way to inform those accusations is to be sat in my house, sadly my GF, our 2 year old and our dog are not admins!

Every time I see a thread on cheating, I think to myself that I am looking forward to being accused of cheating, because it will mean that I have started to play well  

I think you will feel differently when it happens Harter! I dont claim to be a great player, OTB grade is around 150 - 160 ECF 1800 - 1900 Fide. The grades on here dont really equate to the same, if you check your opponents grade OTB online as I have done with a few they are usually a few points lower than it shows on here, but i put a little time into my chess, have a very busy business to run and its a good distraction tbh keeps me grounded... until I apparently cheated! 

Maybe!  You sound like a decent player to me.  I only started playing earlier this year and the time I put in goes through phases.  I love correspondence chess though - I really can't play fast and don't have time to play longer OTB games.  I love going through different combinations but am constantly amazed at how often I miss a really good move that is so obvious when I see it later after I've sent one of the games in for computer analysis.