Official cartridges for the NES come in two flavors, the common 3-screw and the uncommon 5-screw. This refers to the number of screws used on the bottom to hold the cartridge together. You may hear retro gamers and collectors refer to 5-screw carts from time to time and there are people who are surprisingly passionate about this feature that on the surface seems pretty insignificant.
But just as there are coin, comic book and sports card collectors who obsess over tiny details and manufacturing oddities, NES carts are really no different.
In the early days of the NES era, cartridges were assembled using 5 standard flathead screws to hold them together (two at the top, one in the middle and two at the bottom). Not long afterward, the design changed to a 3-screw method (one in the middle, two in the bottom and plastic tabs on the front of the cartridge to form the seal). The screws were also changed to unique head design that requires a specialty bit to remove.
Nobody seems to know the exact reason for the change, but its assumed that using 3-screws in conjunction with plastic tabs lowered manufacturing costs, so everything was switched over to the more common 3-screw versions at some point around 1987.
One of the reasons why 5-screw carts are more desirable is because some of them contain a Famicom-to-NES converter. In the early days of the NES, Japanese PCBs were used in American cartridges due to an oversupply of them in Japan. They needed a converter to fit the different pin layout of the American NES, so the cartridges were made taller than the Japanese Famicom carts in order for this converter to fit.
Before third-party Famicom converters were easily available in North America, using the Famicom converter from certain 5-screw NES cartridges was the cheapest and easiest way to play import games on a North American NES system.
For the most part, the 5-screw versions of games are more sought after by collectors, though only a few particular games sell for significantly more. When Nintendo changed from the 5-screw to the 3-screw format, some games were caught in the middle of the transition, which is why they exist as both 3 and 5-screw variants. However there are a few games where the 5-screw version is the more common and less desirable version, like Donkey Kong and Donkey Kong, Jr.
Here's a complete list of every NES game that you can find as a 5-screw cart:
10-Yard Fight
1942
3D WorldRunner
Alpha Mission
Arkanoid
Athena
Athletic World
Balloon Fight
Baseball
Breakthru
BurgerTime
Castlevania
Chubby Cherub
Clu Clu Land
Commando
Deadly Towers
Donkey Kong 3
Donkey Kong Jr Math
Donkey Kong Jr
Donkey Kong
Double Dribble
Duck Hunt
Elevator Action
Excitebike
Ghosts 'n Goblins
Golf
Gotcha
Gradius
Gumshoe
Gyromite
Hogan's Alley
Ice Climber
Ikari Warriors
Jaws
Karate Champ
Kid Icarus
Kid Niki Radical Ninja
Kung Fu
Legend of Kage
Legend of Zelda
Lode Runner
Lunar Pool
MUSCLE
Mach Rider
Mario Bros
Mega Man
Metroid
Mighty Bomb Jack
Mike Tyson's Punch-Out
Ninja Kid
Pinball
Popeye
Pro Wrestling
Rad Racer
Raid on Bungeling Bay
Ring King
Rush'n Attack
Rygar
Section-Z
Sky Kid
Slalom
Soccer
Solomon's Key
Spelunker
Spy Hunter
Sqoon
Stack-Up
Star Force
Star Voyager
Stinger
Super Mario Bros
Super Pitfall
Tag Team Wrestling
Tennis
The Goonies II
Tiger-Heli
Top Gun
Track and Field
Trojan
Urban Champion
Volleyball
Wild Gunman
Winter Games
Wizards and Warriors
Wrecking Crew
Zanac
So that's the deal with 5-screw NES cartridges. In most cases, if you're out game hunting and see a 5-screw version of a game, its probably more collectible than a newer 3-screw cart.
