Rising Force Online, commonly abbreviated "RF Online" or "RFO," is a massively multiplayer online role-playing game (MMORPG) in which players all over the world can connect to the same servers and interact with each other as warrior avatars. Game characters are on a relentless quest to uncover new weapons, armour, abilities and levels of strength and prowess. This search is aided by the crafting ability, which allows characters to create new items and equipment out of preset materials. The red stones are an example of such materials, and are especially useful in producing shields and armour.
Travel to your civilisation's "hero" character, who facilitates your crafting abilities. The Bellatean hero is "Be Hammer," Accretians turn to Lothan the 3rd, and Corites rely on Jiz Kadasha; these heroes are located at their respective civilisation HQs.
Click on your civilisation's hero to initiate a conversation with him. Select the option which reads "Item Combination" to begin crafting.
Drag items that you wish to combine together into the five empty slots in the new window. It doesn't matter which slot your place your red stone(s) in.
RF Online is a "free to play" MMORPG, meaning that it is free to use the game's servers to play online. Learning recipes in game helps you determine what product will come out of combining certain items.