Craft System is very, very common in nowadays sand box RPG games or action RPG games. It is popular with reasons. Without creating a significant amount of additional game content, a craft system can cater the players' needs of more game choices and being special or unique. In Single Play games, a good craft system encourages players to search the world and build their own property, which, to a great extent, extends the play experience and time invested by the players. In Multiple Online games, craft systems help establish a virtual economy and even a society, which also helps the players connect to each other in a very tight bond. It is a good way to keep player in the game world.
Examples[]
Fallout 4 is a post-apocalyptic role-playing TPS/FPS video game in which players play as a survivor on the earth that was basicly destroyed by a nuclear war. In Fallout4, players can collect everything from debris- cans, toasters, microwaves, coffee machines, and many, many other everyday or highly technical things. Player can break them into usable components and craft new guns, armors and even build your own base. This system makes players invest hundreds of hours play this game.
Skyrim - In Skyrim a player is able to find raw resources throughout the game world which they can then turn into useful items. The player is able to create weapons, armor and even potions which will have positive or negative effects. Players can also enchant items and improve existing items.
Shop Heroes - The facebook game Shop Heroes is almonst entirely focus on crafting and it feels great. The players shop will spawn the resoources they need every few minutes and it is up to the player what weapons/armour they wish to make. Recipies are simply layed out in front of the player and it is simple to construct very interesting and rewarding weapons and armour.
Final Fantasy XIV - The crafting system in FFXIV is thoroughly developed and involves actual classes that are purely designated as crafters and gatherers. These classes have abilities that help them to either craft or gather items with certain skills focusing on making these items higher quality versions of themselves. The classes follow the same leveling system as battle classes do with a level cap of 60 that must be reached through completing quest or just grinding crafts. These classes are so developed that there are even rotations used in order to obtain the optimal results of each attempted craft or harvest. Also, these classes help to create in game market that is highly developed and important for higher level content.
Don't Starve - At the beginning of the game, the player starts with nothing and has to collect items and resources to craft all the necessary items in order to survive as long as possible.In turn, some of the crafted items can be used to gather more resources more efficiently. The player has to know when to craft what in order to maximize the usefulness of the resources since they are, on some level, limited. Along the way, the player needs to craft the correct things at the correct time. From a torch to an amulet, there are lots of possibilities. It keeps players busy and yet accomplished, thus helping players to get more interested in the game.