Within the video game community, PAL is a term used to refer to the region of Europe, most of Asia (minus Japan, South Korea, Taiwan and the Philippines), Africa, most of South America, and Australia. The term comes from the analog television encoding system Phase Alternate Line, which was the primary method of encoding analog TV for these parts of the world. This is opposed to NTSC, which is the standard used in North America and smaller parts of South America and Asia.
There are numerous differences between PAL and NTSC as television formats, but the main difference which affected video games was their refresh rates. NTSC TVs run at 60 hertz (meaning the image refreshes 60 times per second), while PAL TVs only run at 50 hertz (50 refreshes per second), meaning that, unless adjusted to account for the refresh rate, PAL runs at 5/6th the speed of NTSC. An alternative standard that runs PAL at 60 hertz was later developed, so the difference between the formats primarily became their different methods of encoding.
Historically, the PAL version is usually the third and final major version for games made in Japan to be released. This is for numerous reasons: as PAL functions very differently from the NTSC format, games had to be converted to work in the PAL format, and games have to be translated into several languages within the region, whereas NTSC regions have fewer languages to handle (at minimum, only English and Japanese). In addition, due to differences between American English and Commonwealth English, the English translation for the UK and Australia cannot always be simply copied from the American version of the game; the same applies to Latin American Spanish and European Spanish, as well as Canadian French and European French.
As a result, PAL releases were often the final version of Nintendo games, with the chance of the highest amount of bugs fixed, the games being adjusted to run at 50Hz (sometimes resulting in slower gameplay speed), and possibly significant changes added, at least prior to the adoption of online play requiring copies of the games to be compatible with each other.
Though the last Nintendo console to support the analog PAL video signal was the Wii, the term is still commonly used as shorthand to refer to the areas where PAL was formerly used, as the games released there usually use the same version between them.
Summary of PAL releases of the Super Smash Bros. series
Super Smash Bros.
The original Super Smash Bros.'s PAL release has a few differences to the NTSC-U version, retaining all its changes while slightly buffing or nerfing a few characters. Despite the refresh rate difference between PAL and NTSC systems, the game has been optimized to run at a similar speed as the NTSC versions. There are two separate PAL releases; a European and an Austrilian release. The European version has language options for French and German, and Link differs between the two PAL versions. Link was rebalanced in both versions, with Link being nerfed in the Australian release and buffed in the European release compared to his NTSC-U counterpart.
Super Smash Bros. Melee
The PAL version of Melee used the NTSC 1.02 version as its base, but then added balancing changes to several characters, resulting in dramatic metagame differences between the two regions. For example, Falco's down aerial can no longer spike opponents during the late hit, and so is harder to use effectively. Fox, Sheik, and Marth have also been nerfed in notable ways.
While the game still plays in 50 Hz by default, the PAL version can be played in 60 Hz by holding the B button during the boot-up of the game. The PAL version has five languages available; English, French, German, Spanish and Italian, with all languages being available and selectable in all PAL releases.
It should be noted that many of the PAL version's attributes—such as Falco's down aerial and the semi-spike being removed from the entirety of Link's Spin Attack—are used in all versions of Brawl. As a result, it appears that the developers used the PAL version of Melee as the base when developing Brawl. Some changes however (such as the reduced damage on some attacks and Marth's reduced weight) were not carried over to Brawl but instead kept their NTSC values.
Super Smash Bros. Brawl
In order for cross-region online play to be possible, most of the differences between versions of Brawl are purely aesthetic, though they are still encoded differently. PAL versions of Brawl can be played in 50Hz or 60Hz. However, Masterpieces are slightly different in the PAL version, running their PAL 50 Hz versions, as opposed to the NTSC version's NTSC 60 Hz versions. When playing Brawl in 50Hz, the effect this has depends on the game, with some running noticeably slower while others run at more or less the same speed. When playing the PAL version of Brawl in 60 Hz, however, some of the games are still using their PAL versions, but they are sped up to match the higher refresh rate. This results in some masterpieces (such as Super Mario Bros. and The Legend Of Zelda) having much faster music than they are supposed to.
The PAL version of Brawl actually has some skips in The Subspace Emissary which cannot be done in the NTSC versions, which makes the PAL version preferred for speedrunners.
Super Smash Bros. 4 / Super Smash Bros. Ultimate
Neither version of Smash 4, nor Ultimate, use analog connections (Although the Wii U is natively compatible with analog connections); as such, the gameplay is identical in both the PAL and NTSC versions of these games, again accommodating for cross-region multiplayer. However, the PAL version of Smash 4 uses a variety of different names for characters, moves, and items, most notably Duck Hunt Duo, Mii Sword Fighters, Housewarming Party, Duck Jump Duo, and (in both Smash 4 and Ultimate) the Football. Some names and voices are also changed on the Spanish and French languages between both regions. In addition, both Wii Fit Trainers have different voices in the PAL versions, and completely different translations are used for incidental text such as trophy descriptions. Masterpieces, however, are now identical to the NTSC version, running at 60 hertz. As the Nintendo Switch is region free, Ultimate essentially only has one version, with all of its regional differences built into the cartridge.