A clone is a character with a moveset that is almost identical to another character's moveset. Often, the clone's moveset will have a few tweaks made, but on the whole the characters' movesets are similar and typically have the same special move mechanics. Clones may have different physics as well (such as weight or speed).
Clones are a common inclusion in various fighting games, as for a developer it saves a good deal of time to copy a character's moveset and then tweak it than to generate a new one; on the other hand, many fans consider the inclusion of clones to be lazy or uninspired.
A semiclone is a term used as a sort of midway point being "clone" and "non-clone". Semiclones share some of their moveset with another character but have enough unique moves that calling them a "clone" wouldn't be entirely accurate. Different players have different opinions of how unique a character's moveset has to be to move from "clone" to "semi-clone" status: newer players tend to exaggerate the importance of special moves for character comparision, for example.
The process of decloning a character between iterations of a franchise is often known in the Smash community as Luigification, named after Luigi's origin as a palette swap of Mario to becoming his own unique character in the Mario series.
 Clones in Super Smash Bros.
|Mario||Luigi||Luigi's dash attack is a unique move. All three of his special moves have slight differences: Luigi Cyclone launches foes instead of sucking them in, Luigi's Fireballs are immune to gravity, and the Super Jump Punch either does massive damage or almost none. His taunt is also different. Overall, Luigi is faster but weaker than Mario.|
|Kirby||Jigglypuff||Both share similar forward smashes, down smashes, neutral aerials, forward aerials (Kirby's hits multiple times, but he extends both legs in front of him as does Jigglypuff), down aerials, tilts, back throws, item animations, and ledge animations. Both have similar weight, falling speed, and both possess multiple jumps. Their special moves, however, are all different.|
- The Fighting Polygon Team is composed of clones of all 12 playable fighters.
- Metal Mario is an exact copy of Mario, but with more weight and flinch resistance.
- Giant DK is a copy of normal DK, just much larger, heavier, and flinch-resistant.
- Samus and Captain Falcon share neutral aerials, down smashes, back aerials, up tilts, and down tilts, but have enough unique moves of their own to not be classified as semiclones.
- Mario, Luigi, and Ness, interestingly, all share a polygon form, a forward tilt, and a floor recovery attack.
 Clones in Super Smash Bros. Melee
Melee directly identifies its clones by placing them in recessed boxes on the character selection screen.
|Mario||Dr. Mario||While all attacks have identical animations, many of them have different properties, such as with Dr. Mario, the removal of the forward smash's sourspot while dealing electrical damage, a sex kick that gets stronger over time, and a forward aerial that doesn't meteor smash. Dr. Mario's attacks are also a bit stronger in general. Note that they also share the exact same size, shape, weight, and falling speed.|
|Link||Young Link||Like the Mario/Dr. Mario pair, while all animations are essentially identical, most attacks act differently. Young Link's forward smash has weak, set knockback on the first hit and only combos into the second hit, while his arrows are on fire and his Spin Attack is a multi-hit move when grounded. Young Link is also faster and weaker than Link.|
|Fox||Falco||All attacks have (near)identical animations and functions, though many have had their knockback altered, changing which ones are good for KOing, such as Falco's forward smash and down tilt being considerably stronger than Fox's, while Fox's up smash and up aerial are considerably stronger. Falco's special moves have identical mechanics but have changed enough that they have different applications; for example his Blaster shots flinch and his Reflector produces vertical knockback instead of semi-spike trajectory horizontal knockback. Falco also runs slower and jumps higher than Fox, while being slightly heavier, and has a down aerial that hits only once.|
|Pikachu||Pichu||Pichu's up smash is a headbutt instead of a tail flip, its down smash emits no electricity while only hitting once, and its forward smash is a multi-hitting attack. Their special moves, while identical in name and animation, have some differences, as Pichu's Skull Bash can be charged longer and gain more power, Thunder is a multi-hitting attack, and Agility travels further than Quick Attack, while not having hitboxes and being slower. Pichu also damages itself for every electrical attack it uses.|
|Captain Falcon||Ganondorf||While most attacks have near identical animations with similar functions, many of them are carried out slower for Ganondorf, and most if not all have elevated power. Ganondorf's forward air and neutral attacks are unique, and his down special can spike when used in the air. Ganondorf is also heavier while being slower with less air speed and jumping height, along with slower falling speed. This is the only clone pair where both characters do not come from the same universe. They share a dash attack and up tilt (though differing in effect for each) with Samus, whose remaining moves are unique.|
|Marth||Roy||As Roy's sweetspot is at the hilt of his sword instead of the tip as with Marth's, even attacks that appear to be unchanged (that is, almost all of them) must be used differently. Nonsweetspot differences include Blazer being a multi-hit move with set knockback, Counter having a multiplier for determining the strength of the counter strike, and a sweetspotted up smash being a spike. This is the only clone pair where both the original and the clone are unlockable characters.|
|Mario||Luigi||Luigi's many changes from SSB to Melee have distanced him from Mario considerably. In addition to his previous differences, he now has a unique forward smash, up tilt, neutral combo, forward aerial, and side special; his other specials have also been further tweaked, such as the Super Jump Punch no longer giving horizontal distance.|
- In the transition from Super Smash Bros. to Melee, characters like Jigglypuff and Captain Falcon have been differentiated with new attacks. In Jigglypuff's case, it has kept some of its moves from SSB, while Kirby has received new ones.
- As Luigi and Dr. Mario share a "parent" in Mario, it stands to reason that the two are semiclones of each other in some way. This kind of relationship is generally not considered in the definition of "semiclone", however.
- Samus, Captain Falcon, and Ganondorf all share floor recovery attacks and have similar up tilts.
- Bowser and Giga Bowser are clones, having identical movesets, although most of Giga Bowser's moves have some sort of additional effect along with altered knockback.
- The Male and Female Wire Frames are clones of Captain Falcon and Zelda, respectively. They lack special moves, however.
- Master Hand and Crazy Hand can be considered clones, as they share most of their attacks.
 Clones in Super Smash Bros. Brawl
While there is considerable grey area on the subject, it can be said that Brawl contains no true clones; rather, it only contains semiclones - and even this can be disputed at length.
|Mario||Luigi||With the Mario Tornado changing from Mario's down special to his down air, Luigi is even more differentiated to the point of possibly not being a semi-clone. More attacks have been changed from Melee to Brawl, and Luigi has for the first time been given his own voice, instead of Mario's sped up voice samples.|
|Link||Toon Link||One of the more disputed pairs, as some players believe they have enough similarities to be considered clones rather than semi-clones. Toon Link's unique attacks include his up smash, neutral aerial, forward aerial, forward throw, and back throw, while his down aerial is a stall-then-fall that meteor smashes, and his forward smash functioning like a multi-hit smash, despite both having similar animations to Link's counterparts. On the other hand, all special moves are clones from Link (the aerial Spin Attack's hitboxes are 99% identical), and some moves were not even programmed properly (Toon Link's forward throw is considered a Leg attack like Link's even though it's obviously a shoulder tackle). However, they are completely different in other statistics, such as size, shape, weight, and walking/dashing/falling/air speed.|
|Fox||Falco||Falco now has a different dashing animation, neutral combo, up tilt, forward smash, neutral aerial, forward aerial, back aerial, and up aerial. He also uses his Reflector differently, but otherwise all his special moves (including his Final Smash) remain cloned (identical mechanics with minor alterations).|
|Captain Falcon||Ganondorf||Ganondorf's forward tilt, down tilt, up smash, up throw, and forward special are now unique, along with other attacks receiving an alteration in animation, such as Ganondorf's dashing animation, up tilt, down smash, neutral aerial, down aerial, Warlock Punch, Dark Dive, and Wizard's Foot. However, other standard attacks are still near identical in animation/function, and while the similarity of Flame Choke and Raptor Boost is disputable, their other special moves are very similar in function. Other differences they had in Melee still exist in Brawl.|
|Ness||Lucas||Lucas's standard attacks are unique with the exception of his forward smash and up aerial; however their special moves are very similar in name and appearance, while having similar functions with differing mechanics. Note that in addition, both have very similar size, shape, weight, and falling speed, along with both suffering from 10 additional frames of lag when being grab released.|
- The Alloys are all clones: Red Alloy of Captain Falcon, Blue Alloy of Zelda, Yellow Alloy of Mario, and Green Alloy of Kirby.
- Even Master Hand and Crazy Hand have each been Luigified, with Master Hand now having unique moves and separate functions in his attacks.
- Many newer players tend to assume Fox and Wolf are semi-clones, or even full clones, due to their special moves and Final Smashes being similar in name, and mostly identical in operation. However, closer inspection of their movesets shows that even calling them semi-clones is difficult to rationalize, as their special moves are noticeably different in function and appearance, the characters' physics are radically different, and none of their standard moves are similar.
|Young Link||Toon Link||Both younger Links share very similar set of differences with Link - they're smaller, faster, have less reach in their attacks, and both have more controllable Boomerangs and multi-hitting Spin Attacks while having a forward smash that is identical in function. It is commonly assumed by players that Toon Link is essentially Young Link with a different coat of paint, in the same way that Link's apperances in Melee and Brawl originate from different Zelda games.|