Twelve is the number of difference. For example: the pages aren’t numbered in the 5th edition, but if there was a page 12, it would have the information on equipping your characters on it. In 7th edition, page 12 is a description of Warriors.
12A is the random treasure table in Buffalo Castle. Oddly enough, it only has 6 treasures in it.
12 is the best number you can roll on 2D6, especially when trying to make a saving roll. Doubles add and roll over.
IN T & T 5.5 we offered the Mike Stackpole system of skills for T & T. IQ 12 was what you needed to get the First Aid skill. I don’t know if Mike ever used his Intelligence based system of skills in a T & T game. I’m sure he used it a lot in Mercenaries, Spies and Private Eyes. And we used it in the computer game Wasteland.
In 5th edition it took 280,000 adventure points to reach 12th level.
Section 2.12 describes the various character kindreds in the 5th edtion.
12 is the number that you had to roll for every attribute to gain a warrior-wizard in the 5th edition. Back in the day, we calculated what the odds were against rolling 6 12s or better on 3D6 in sequence. A quick calculation shows there are only 9 combinations of 3D6 that total 12 or higher. 9/36 reduces to 1/4. That means the odds of fairly rolling a warrior wizard 1/4 to the 6th power or 1 in 4096 or 4095 to 1 against it happening. We love long odds in Tunnels and Trolls. The odds come down a little if you use the TARO rule to get additional rolls for the triples: one one one, two two two, and three three three. In the beginning we didn’thave a TARO rule.
If you can think of some good 12s in Tunnels and Trolls, please add them into the comments below, and come back tomorrow when I talk about lucky number 13.