Whether due to a different philosophy of design or due to alien biology, the Gadget’s interface is not intuitive to the operator.
As a Minor Bad Trait, the Gadget is simply awkward to use – a UNIT soldier may have to hold a laser pistol designed for a larger creature like a rifle. The character has a -2 penalty on any attempts to use the Gadget.
As a Major Bad Trait, the character needs to succeed at a Difficulty 18 roll of an appropriate Attribute + Skill combination before they can even use the device and even then they still receive the penalty as for the Minor Bad Trait.
An example of this is Zygon bio-technology, which requires the user to succeed on an Ingenuity + Science roll before using such a Gadget, and even then still with the -2 penalty.