Alien Technology

Source: Dungeon Master’s Guide p. 268

When adventurers find a piece of technology that isn’t from their world or time period, the players might understand what the object is, but the characters rarely will. To simulate a character’s ignorance about the technology, have the character make a series of Intelligence checks to figure it out.

To determine how the technology works, a character must succeed on a number of Intelligence checks based on the complexity of the item: two successes for a simple item (such as a cigarette lighter, calculator, or revolver) and four successes for a complex item (such as a computer, chainsaw, or hovercraft). Then consult the Figuring Out Alien Technology table. Consider making the item break if a character fails four or more times before taking a long rest.

A character who has seen an item used or has operated a similar item has advantage on Intelligence checks made to figure out its use.