Cheap is a word that has been used to complain about almost any aspect of a game. Because of this, it has no clear meaning. The closest definition is "a strategy that someone can not figure out how to beat" or "a strategy that is seen as unfair or in poor sportsmanship". However, there is usually no rule against these tactics in tournaments because they are subjective. Many times, players cry cheap about any style that prevents them from performing their top moves, or even just prevents them from winning. To date, there are no tactics or characters banned in the Super Smash Bros. series simply for being "cheap". Tactics that truly are so "cheap" that they completely destroy the game are considered broken.
A "John" is a cheap excuse for losing, missing a recovery, being hit by an attack, or any number of unfavorable events in Super Smash Bros. It is a statement or action that detracts from the validity or quality of a competition (or its implied significance), irrespective of truth.
The term John, according to California smasher HugS, comes from a Smash player in Texas (named John) who would consistently invent excuses every time he lost. The term "Johning" became commonplace in the community, as others grew tired of his excuses, thus coining the term.
The phrase "No Johns" or simply, "Johns!" means "no excuses". It is frequently used as a retort when another player uses an excuse.
In Europe, there are some variations of this phrase:
In Sweden, the term "Yuna" can be used interchangeably with "John", here referring to the Smasher, Yuna, who has the same habit. It's most commonly said almost completely in Swedish, "Inga Yunas".
In Spain, there are a lot of synonyms to the term "John". It is commonly overheard "No Veyrons" (especially in northern Spain) or "No Joshis" (more common in the south). This is because of Veyron, a Catalonian smasher, and Joshi, an Andalusian smasher; that both have the habit of making up excuses every time they lose.
In Italy, for a certain period of time, the expression "No Dems" was used, referring to Dem-Long, a player from Florence who didn't pass pools in a tournament in June 2006 with the claim that "his hands were too cold."
In Germany, during early Brawl times, a counterpart evolved: "No Stacos", which leads back to the player Staco. He frequently made up excuses for why he lost, or even when he won ("I could have done better"). While this is past, the phrase is still commonly used, especially when he himself comes up with this phenomenon. As an extra in written form, the digit sequence "<<" was established by him, stressing his disapproval when something was not in his favor. Throughout the community, this is being called kleiner als kleiner als (less than less than).
In France, the expression "No Micks" is used, referring to the player "Garian" (he's named Mickael) who is always trying to make excuses by losing in Wi-Fi. In the real life, at offline tournaments he throws his controller when he loses.
The term "cheap" originally comes from the financial term "cheap", which describes an item where its value exceeds its cost. The term has since been used to describe anything from tactics to items to characters as things that are inexpensive to perform or deploy that yield a high payoff. Such things are seen as questionable among players who value skill-based play, as things that are considered cheap disrupt an environment where skill is supposed to determine the outcome, since little skill is involved in "cheap" tactics or characters, but the payoff is higher than expected.
To untrained players or players who have not undergone extensive practice, many moves and tactics that yield unexpectedly high payoffs may seem "cheap" - this is because tactics or moves, when used by professionals, sometimes seem easy to pull off, making the tactic or move appear to perform better than expected. Players unaware of the skill required to execute such tactics yet still cry "cheap" make a premature judgment of the tactic without fully understanding what is required to execute it well.
For example, a common referred to "cheap" tactic would be known as Kirbycide/Suicidedede where a character that can encapsulate an opponent and has an extra life compared to their opponent will stand at the edge and wait for them to come close, use their Neutral B (usually a sucking move) and fall off of the stage together with their enemy in their "belly." This causes the Kirby/Dedede to lose 1 stock, but it also causes the opponent to lose a stock as well, ultimately defeating the opponent. Criticism for this tactic is deep-rooted since Melee with Kirby, and has been considered cheap ever since.
Naturally, as games have become more complex, players find it harder and harder to objectively define the value and cost of tactics or character moves. The subjectivity in defining a "cheap" move and the inability to distinguish ease of execution with second-nature skill both obscure the natural use of the term "cheap", subverting the word into an umbrella term that is more often used to describe an aspect of a game the player is displeased with.
Tactics or characters that are considered "too cheap" are often considered "broken". The blurring between these two terms often confuses players new to competitive gaming; as such, both terms have become somewhat interchangeable despite having fundamental differences.