There are two ways to engineer items-combination and manufacture. Combination is that selecting the option of combination on the interface ingame and using "Melt Stove" in the combination list. Then combine 2 items or more into one. And the Manufacture is that using equipment at home to produce things which are much more valuable.
Melt Stove Combination

"Melt Stove Combination"can directly use in anywhere and anytime. It doesn't take any times to have the combined items. But there's a higher un-certain possibility when you combine something. And it does increase the feeling of novelty and expectation. Therefore, you may combine something which is really good when you have some regular items.
Rome Warrior Helmet
Brave ancient Rome warrior engineered this high protection helmet in order to protect their heads.
+ defense

Toothed Stick
In order to increase the power of stick, people added sharp iron
thorns on it. It's a weapon which makes enemies feel afraid.
+ attack

A special tricky weapon. Enemy is hard to defend when run into this kind of weapon due to the power and speed of shuriken.

Manufacture items

"Manufacture items"Players need to select the
combination equipment at home to produce items you want.

Be careful of that each production has a certain method and material. Although it takes time, you can have special functions and various equipment.

Match Series:Long, Short Pistol
Pistols which engineered in early of western. There is a rope and fuse. When fires can explode the gunpowder in the barrel. It can shoot lead bullets to attack enemies. It can also have long-distance attacks, but not convenient to reload bullets.

A mechanism weapon was designed while technology is getting better. When firing pin strikes gunpowder, it will be exploded. It's a great weapon using in long distance.

Mixed with iron nail and lots of gunpowder. Throw it when it is fired. Great wounded range after explosion.

Using missile to replace bullet. You need to calculate the parabola when attack enemies. Great power and surprising lethality.