One first I’ve been curious about is the first game to us a ‘Tetris’ style inventory system where you had to fit different block shaped items in a grid representing your inventory. It is very common, but someone did it first.
What about the first to use a slot inventory at all?
In 1984 "Sundog: Frozen Legacy", first on the Apple ][e then on the Atari ST is the earliest example I remember of a game with a slot inventory.
You couldn't yet put something "twice the size", using two blocks but you could already move inventory from character to your vehicle or to your spaceship's cargo.
