https://crossingtheverse.wordpress.com/2019/01/26/on-an-analysis-of-2nd-edition-magics/
On an analysis of 2nd Edition magics – Crossing the ‘Verse
Sanctioned Cambion – or D&D Hellboy
The Cassowary
Mothers tell their children The Cassowary strikes by candlelight.
Thieves, murderers, the corrupt: you see a flickering flame in the bush you are finished.
The Age of Macquarie
A view of part of Parramatta Port Jackson, J.W. Lewin, 1809. Courtesy State Library of New South Wales
http://www.migrationheritage.nsw.gov.au/exhibition/objectsthroughtime-history/1790-1830/index.html
” Around this time Matthew Flinders was exploring the coastline of New South Wales and New Holland. In 1802 – 1803 Finders circumnavigated the continent and was the first person to use the term Australia when referring to the whole continent of New Holland, New South Wales and Van Diemens Land. “
The Colony at Sydney Cove was closing to starving in the late 18th century, Macquarie took over in 1810, getting rid of Bligh etc. Australian rebellion! Good turmoil and opportunity.
Historical Colonial Population of Australia
In 1820, around 36,000 immigrants in New South Wales.
So, a small population of possible Player Characters with those numbers.
Mokuy Picture 1
First Public Railroads in Australia
” New South Wales: In 1849, the Sydney Railway Company started building the first railway track in New South Wales between Sydney and Parramatta—a distance of 22 km. The project ran into financial difficulty and was taken over by the New South Wales colonial government. The line opened on 26 September 1855. “
https://infrastructure.gov.au/rail/trains/history.aspx
So for an 1820s each set Australian game, prototypes by your crazy science types are very likely..
D&D Armor Class
Originally when I started playing, you just looked up an Attack Matrix. This listed the number to hit an Armor Class based on the character class and level. Armor Class was Descending, so lower was better. Once you knew one AC, of course, a simple calculation gets you the rest. You need a 19 to hit Armor Class 0 then obviously a 17 to hit Armor Class 2. Moldvay Basic or AD&D.
This of course led to the second edition and recording the To Hit Armor Class 0 number or THACO on a character sheet.
Another way to calculate this, which gets used in Stars Without Number 1st Edition for example:
d20 + modifiers + AC >= 20
Here you have at a simple level, an attack bonus for example. If this is +2 and the AC of the opponent is 5 then you need d20 + 7 >= 20 or a 13 to hit. If instead of wearing Chain the opponent is wearing Plate, then it would be a 15 to hit.
Then we have a current version of Ascending Armor Class where the Armor Class listed is the target number to hit.
d20 + modifiers >= AC
Yoon-Suin Links & Resources
Is Your D&D Character Rare?
A sample taken by 538 from D&D Beyond :-