In Hogwarts Legacy, the Grand Staircase is a huge magical staircase that spirals up into a large tower in Hogwarts School of Witchcraft and Wizardry. It’s also one of six areas in the school and the location of two of those tricky puzzle doors that require you to do arithmetic on images of mythical and magical creatures. One of these puzzle doors is very close to the large fireplace in the Flame Stair Tower.
Related: All Daedalian Key locations in Hogwarts Legacy
How to Open the Grand Staircase Tower Puzzle Door in Hogwarts Legacy
Gamepur screenshot
If you’ve already unlocked the Floo Flame from the Grand Staircase tower, quickly head over to this one. Otherwise, set it as a waypoint on the map and walk or run towards it. If you head up the grand staircase, you might spot the puzzle door on the outside wall as you go up. Otherwise, start at Grand Staircase Tower Floo Flame and go down Grand Staircase a bit. The puzzle door is on the west wall.
Gamepur screenshot
The first thing you need to know is that the creature icons around the door are numbered, left to right, from 0 to 9, so each time you see one it represents a number. To unlock the door, the numbers at the ends of the two triangles must match the numbers inside the triangles, so you need to rotate the triangles near the door so they display the correct icon. The upper triangle indicates 15 + dragon (2) + ? = 23, so it throws the “?” triangle (on the wall just above the stairs) until it shows a salamander (6).
Gamepur screenshot
The bottom triangle indicates hydra (3) + snakes (9) + ?? = 19, so discard the “??” triangle (directly in front of the door) until he points to a squid (7). You can now open the door, which leads to a small, elegant room with two chests, one of which contains the Puffskein Statue Conjuration Scout collectible.
Source