Randomness

Randomness, also referred to as random number generation (or RNG for short), is the concept of unpredictable events. It is a critical factor in many video games, including the Super Smash Bros. series and, consequently, the Super Smash Flash series it inspired, as well as the Yeah Jam Fury series to a much lesser extent. Random events often challenge players to think quickly and cause a game to never be played the same way twice.

Very few random elements appear in the original Super Smash Flash, due to the extremely limited nature of the game overall. This was changed in the reboot, Super Smash Flash 2, where the improved engine and similarities to the official Super Smash Bros. games allow for more to occur. Several random elements also appear in Yeah Jam Fury, and the follow-up Yeah Jam Fury: U, Me, Everybody! expanded upon them. Unlike with the Super Smash Flash games, most of the random elements in the Yeah Jam Fury games are purely cosmetic and do not directly affect gameplay.

Mechanics of computer-generated random numbers
Computers are unable to generate truly random numbers. They can only create a series of pseudo-random numbers. If a computer were to start out with a certain seed (initial number), one could predict the entire sequence of pseudo-random numbers to follow. It is believed this is how replays are saved; the system only saves the seed instead of all random events.

General

 * Computer players do things randomly: the higher the computer's level, the more likely it is to do a specified action.
 * Random items appear in predetermined places at random times, with preset ratios.

Game modes
The following are random occurrences that apply to certain game modes.


 * Some levels in Classic have the opponents randomly selected between certain characters.
 * The opponent in Level 1 is randomly selected between, and , as well as  and  when unlocked.
 * The opponent in Level 4 is randomly selected between, and , as well as  when unlocked.
 * The order in which opponents are fought in All-Star are randomly chosen upon playing the mode.
 * In Multi-Man Melee, each Silhouette character is randomly selected upon appearing (except in Burly-Brawl Melee, in which each Silhouette is the same randomly selected character).

General

 * Computer players do things randomly: the higher the computer's level, the more likely it is to do a specified action.
 * Random items appear in predetermined places at random times, with preset ratios.
 * In matches with more than two players, each player enters the stage at a predetermined place that is randomly chosen.
 * KOs that occur on the upper blast line are randomly chosen from being either a Star KO or a Screen KO.

Random character/stage select

 * The character selection screen has a designated space for choosing a random character, referred to as "Random". A "?" appears on the player's selection bracket and no one will know who that player will be until the match begins (The system will choose and begin loading the character as soon as Random is selected, however). This random function also selects a random palette swap for the character, and is how CPUs are entered by default.
 * A random stage can be selected in a similar way on the stage selection screen, with a space referred to as "Random" designated for a random stage to be selected. Players can choose which stages not to include in this selection process using the random stage switch.

Characters
The following are random occurrences that apply to individual characters.


 * When uses Sing, each of the three musical notes surrounding it as it sings is randomly selected between two different kinds.
 * can transform into one of six different objects when he uses his down special move, Stone. This only affects the move aesthetically, and has no effect on gameplay.
 * The chance of 's side special move, Green Missile, misfiring is 12.5% on the ground and 8% in the air.
 * 's side special move, Judge, has 9 randomly-chosen attacks, each with different strengths and effects. The chance of pulling each number is equal.
 * The food tossed from Mr. Game & Watch's neutral special move, Chef, travels in the air randomly.
 * After making a full loop, 's Galaxian will randomly fly either straight or in a 30° or 45° angle.
 * PAC-MAN's standard taunt, NAMCO Roulette, will randomly choose between 17 different NAMCO characters or items to show.
 * 's forward smash can hit with 3 different weapons: a frying pan, a golf club or a tennis racket. Each weapon has an equal chance of being pulled, and the same weapon will not be pulled twice in a row.
 * Peach's down special move's Vegetables can have a variety of random faces, with the faces signifying the power of the turnip. The most powerful turnip, which has stitches on its face, has a very low chance of being pulled. There's also a very small chance of an item or an Oddish being pulled instead of a vegetable, and the chance of pulling these items is not affected by whether they are turned on or not.
 * The Capsule plucked from 's standard special move, Capsule Spawn, features all of the random attributes of a normal Capsule.
 * ' down taunt generates randomly timed jumping and explosion sound effects, as well as randomly timed shocked expressions on his face.

Stages
The following are random occurrences that occur in specific stage.


 * After picking the stage, the wallpaper in the background of Desk is chosen at random from one of three designs. In addition, the desk itself is cluttered with a random assortment of items scattered haphazardly around the foreground and background of the stage, but will be tidy on rare occasions.
 * On Galaxy Tours, the layout of Starship Mario is randomly chosen from one of five platform layouts. Similarly, the background is randomly chosen from one of three.
 * The color of the Nintendo 3DS stage is randomly selected after picking the stage from one of nine colors. There are colors that have more chances to appear than others, with the rarest being the Orange and Green variants, which have a chance of appearing of 1/400.
 * The Nintendo 3DS stage layout changes at set intervals based on one of three indie games, which are chosen at random.
 * Switches and Banzai Bill will appear on Princess Peach's Castle at random.
 * On WarioWare, Inc., the stage transforms into a randomly chosen microgame. When a player wins one of these microgames, they are randomly rewarded with the effects of a Super Star, Super Mushroom, Food or nothing.
 * On Yoshi's Island (64), Shy Guys appear at random in packs up to six, which carry food if items and food are turned on. These Shy Guys can be attacked, and will drop their food if carrying it.
 * Similarly, Yoshi's Story features the same Shy Guy behavior.

Items
The following is random behavior of specific items.


 * Which items appear from container items such as Capsules and Party Balls is chosen randomly from what items turned on. There is also a random chance of containers not containing any items and instead being explosive.
 * When food spawns, the specific food that appears is random.
 * What Pokémon a Poké Ball spawns is random, with each Pokémon having a different chance of appearing. If the Pokémon targets a specific player, which opponent is targeted is also chosen at random.
 * The food tossed by Delibird is chosen at random, as well as the Rocket Bombs he may occasionally toss.
 * Like with Poké Balls, which character an Assist Trophy spawns is chosen randomly. If the Assist Trophy targets a specific player, which opponent is targeted is also chosen at random.
 * When Excitebike is summoned, the color palettes of each racer are chosen randomly.
 * The spell cast by White Mage is chosen at random.
 * Smart Bombs occasionally fail to explode when thrown or hit. They will eventually explode if left uninterrupted, or will explode if they come in contact with a hitbox that deals flame damage.
 * If all possible targets have exactly the same damage and score/number of stocks, then the Spiny Shell will pick a target at random.

Game modes
The following are random occurrences that apply to certain game modes.


 * In Classic, the opponents, allies, and stages in Levels 1, 2, 3, 5 and 6 are randomly selected. The Target Smash level is also randomly selected.
 * In Multi-Man Smash, each Silhouette character is randomly selected upon appearing.
 * Several events contain random elements.
 * In Role Reversal, the opponent is randomly selected.
 * In The Power of Random, the player character, opponents, and stage are all randomly selected. Additionally, each character will hold randomized items at all times.
 * In Bob-omb Battlefield, Bob-ombs appear in predetermined locations in a random order.

Levels

 * There is a 10% chance for Style-themed levels to instead be Horror-themed when started, which removes the simplified texture of sprites and allows for Mr. Super to appear in the background.
 * In the level Oh Love, there are two songs that may play when the level starts – Harmony and Fabulous Secret Powers – both of which have a 50% chance of playing.

Levels

 * On most level themes, including Sky, Factory, Desert (Light), and Winter, the color of the mango is randomly selected at the start between red, orange, and yellow.
 * The background and music of many Sky-themed levels is randomly selected between one of three types: Day, Night, and Stormy.
 * There is a 10% chance for Style-themed levels to instead be Horror-themed when started, which removes the simplified texture of sprites and allows for Mr. Super to appear in the background.
 * On the level Oh Love, there are two songs that may play when the level starts – Harmony and Fabulous Secret Powers – both of which have a 50% chance of playing.

Game modes
The following are random occurrences that apply to certain game modes.


 * Each level in the Shuffle game mode is selected at random between either the A-Sides, B-Sides, or both sets at once.

Trivia

 * In SSF2, the random character space on the character selection screen counts as a separate character on Classic mode and Stadium, including a separate score.
 * Selecting it in Classic mode will change the character that the player uses with every round, and clearing it will yield a unique congratulations screen.
 * Clearing Classic mode with the random "character" on normal difficulty or higher without using continues will cause to challenge the player in a 1-stock match on Waiting Room, where victory over it will unlock it.