Leadwerks uses a left-handed coordinate system. This means that if you hold your left hand as shown below, your middle finger, index finger, and thumb will point in the directions of the X, Y, and Z axes, respectively.
Rotations use the left-handed rotation rule. To predict the direction of positive rotation, curl your fingers on your left hand and point your thumb in the direction of the rotational axis. Your fingers will curl in the direction of positive rotation along that axis.
This will help you remember how your rotation values affect objects in 3D space.