Please do not read if you wish to not know!
The Tavern Basement is a secret room that is accessible by unlocking the Ultimate Defender achievement. It appears to serve as a dungeon, with several chains and torture devices placed around the room.
The room is accessible from the ground floor. A neon 'Open' sign will glow upon unlocking the Ultimate Defender achievement.
The room contains the remains of the real Tavernkeep locked in chains with a sword through his neck, revealing the current Tavernkeep as an imposter.
Opening the rear vault increases the player's inventory by 50 slots to 270.
The room contains an uninteractable miniature arcade and a radio to allow players to alter the tavern music.
On the left of the arcade machine closest to the Tavernkeep's skeleton is written:
"I want to play a game. 7 -> 127 -> 2147483647 -> 170141183460469231731687303715884105727"
- The note is a reference to a series of the smallest double Mersenne numbers. These first four double Mersenne numbers are also double Mersenne primes. The next four double Mersenne numbers are known to be nonprime; the next possible prime in this sequence is approximately 1.695E10694127911065419641, but this number is far too large for any currently known primality test.
- 170141183460469231731687303715884105727 is the highest signed 128-bit integer, and has relevance in certain fields of computing (e.g. IPv6 addresses).