In Sid Meier's Civilization and Civilization II, certain game actions occur at regular four-turn intervals, colloquially known as "oedo years". The term is named after the forum user oedo, who first documented the pattern as the "xxxo rule".[1]
Oedo years are most commonly associated with meta strategies to minimize anarchy. They also provide forecasts for barbarian piracy. Oedo years may link to other mechanics, but these have not been documented.
Overview[]
An oedo year occurs every fourth game turn. On this date, anarchy ends and civilizations can adopt a new government.[1][2] A common player strategy in Civilization II is to time research to acquire a government advance on the oedo year, as the prompt to change government occurs before anarchy is resolved in the update process; thus, anarchy's disruptive effects can be partially or fully bypassed.[1]: post 5 Otherwise, instigating a revolution the turn before the oedo year minimizes anarchy's duration;[note 1] the Pyramids (Civ1) and Statue of Liberty (Civ2) Wonders provide the same effect.
Seaborne barbarians spawn on oedo years. The exact onset date is determined by the player's difficulty level,[note 2] after which new pirates appear every two oedo years (8 turns) as permitted by game rules.[3]: post 19 It is less clear whether land-based hordes follow oedo cycles.[note 3]
Reference charts[]
Tracking oedo years is complicated by the lack of an in-game turn counter.[note 4] As a standard game progresses, the interval between calendar dates narrows. The following tables provide easy reference for oedo turns and their corresponding calendar year.
Sid Meier's Civilization[]
The Civilization calendar progresses at a common pace for all difficulties.[4]
| 4000 BC–300 AD Turns 1–219 |
380 AD–1881 AD Turns 220–435 |
1885 AD–2100 AD Turns 436–650 | |||||
|---|---|---|---|---|---|---|---|
| Turn | Calendar date | Turn | Calendar date | Turn | Calendar date | ||
| 4 | 3940 BC | 220 | 380 AD | 436 | 1885 AD | ||
| 8 | 3860 BC | 224 | 460 AD | 440 | 1889 AD | ||
| 12 | 3780 BC | 228 | 540 AD | 444 | 1893 AD | ||
| 16 | 3700 BC | 232 | 620 AD | 448 | 1897 AD | ||
| 20 | 3620 BC | 236 | 700 AD | 452 | 1901 AD | ||
| 24 | 3540 BC | 240 | 780 AD | 456 | 1905 AD | ||
| 28 | 3460 BC | 244 | 860 AD | 460 | 1909 AD | ||
| 32 | 3380 BC | 248 | 940 AD | 464 | 1913 AD | ||
| 36 | 3300 BC | 252 | 1010 AD | 468 | 1917 AD | ||
| 40 | 3220 BC | 256 | 1050 AD | 472 | 1921 AD | ||
| 44 | 3140 BC | 260 | 1090 AD | 476 | 1925 AD | ||
| 48 | 3060 BC | 264 | 1130 AD | 480 | 1929 AD | ||
| 52 | 2980 BC | 268 | 1170 AD | 484 | 1933 AD | ||
| 56 | 2900 BC | 272 | 1210 AD | 488 | 1937 AD | ||
| 60 | 2820 BC | 276 | 1250 AD | 492 | 1941 AD | ||
| 64 | 2740 BC | 280 | 1290 AD | 496 | 1945 AD | ||
| 68 | 2660 BC | 284 | 1330 AD | 500 | 1949 AD | ||
| 72 | 2580 BC | 288 | 1370 AD | 504 | 1953 AD | ||
| 76 | 2500 BC | 292 | 1410 AD | 508 | 1957 AD | ||
| 80 | 2420 BC | 296 | 1450 AD | 512 | 1961 AD | ||
| 84 | 2340 BC | 300 | 1490 AD | 516 | 1965 AD | ||
| 88 | 2260 BC | 304 | 1515 AD | 520 | 1969 AD | ||
| 92 | 2180 BC | 308 | 1535 AD | 524 | 1973 AD | ||
| 96 | 2100 BC | 312 | 1555 AD | 528 | 1977 AD | ||
| 100 | 2020 BC | 316 | 1575 AD | 532 | 1981 AD | ||
| 104 | 1940 BC | 320 | 1595 AD | 536 | 1985 AD | ||
| 108 | 1860 BC | 324 | 1615 AD | 540 | 1989 AD | ||
| 112 | 1780 BC | 328 | 1635 AD | 544 | 1993 AD | ||
| 116 | 1700 BC | 332 | 1655 AD | 548 | 1997 AD | ||
| 120 | 1620 BC | 336 | 1675 AD | 552 | 2001 AD | ||
| 124 | 1540 BC | 340 | 1695 AD | 556 | 2005 AD | ||
| 128 | 1460 BC | 344 | 1715 AD | 560 | 2009 AD | ||
| 132 | 1380 BC | 348 | 1735 AD | 564 | 2013 AD | ||
| 136 | 1300 BC | 352 | 1752 AD | 568 | 2017 AD | ||
| 140 | 1220 BC | 356 | 1760 AD | 572 | 2021 AD | ||
| 144 | 1140 BC | 360 | 1768 AD | 576 | 2025 AD | ||
| 148 | 1060 BC | 364 | 1776 AD | 580 | 2029 AD | ||
| 152 | 980 BC | 368 | 1784 AD | 584 | 2033 AD | ||
| 156 | 900 BC | 372 | 1792 AD | 588 | 2037 AD | ||
| 160 | 820 BC | 376 | 1800 AD | 592 | 2041 AD | ||
| 164 | 740 BC | 380 | 1808 AD | 596 | 2045 AD | ||
| 168 | 660 BC | 384 | 1816 AD | 600 | 2049 AD | ||
| 172 | 580 BC | 388 | 1824 AD | 604 | 2053 AD | ||
| 176 | 500 BC | 392 | 1832 AD | 608 | 2057 AD | ||
| 180 | 420 BC | 396 | 1840 AD | 612 | 2061 AD | ||
| 184 | 340 BC | 400 | 1848 AD | 616 | 2065 AD | ||
| 188 | 260 BC | 404 | 1853 AD | 620 | 2069 AD | ||
| 192 | 180 BC | 408 | 1857 AD | 624 | 2073 AD | ||
| 196 | 100 BC | 412 | 1861 AD | 628 | 2077 AD | ||
| 200 | 20 BC | 416 | 1865 AD | 632 | 2081 AD | ||
| 204 | 60 AD | 420 | 1869 AD | 636 | 2085 AD | ||
| 208 | 140 AD | 424 | 1873 AD | 640 | 2089 AD | ||
| 212 | 220 AD | 428 | 1877 AD | 644 | 2093 AD | ||
| 216 | 300 AD | 432 | 1881 AD | 648 | 2097 AD | ||
Civilization II[]
Progression of the in-game calendar varies by difficulty level and map size; therefore, oedo years will correspond to different dates depending on the particular game's turn limit.[1]: post 13
| Turns 1–287 | Turns 288–570 | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Turn | Calendar date by total turns |
Turn | Calendar date by total turns | |||||||
| 570 | 520 | 470 | 420 | 570 | 520 | 470 | 420 | |||
| 4 | 3940 BC | 3850 BC | 288 | 1370 AD | 1685 AD | 1824 AD | 1887 AD | |||
| 8 | 3860 BC | 3650 BC | 292 | 1410 AD | 1705 AD | 1832 AD | 1891 AD | |||
| 12 | 3780 BC | 3450 BC | 296 | 1450 AD | 1725 AD | 1840 AD | 1895 AD | |||
| 16 | 3700 BC | 3250 BC | 300 | 1490 AD | 1745 AD | 1848 AD | 1899 AD | |||
| 20 | 3620 BC | 3050 BC | 304 | 1515 AD | 1756 AD | 1853 AD | 1903 AD | |||
| 24 | 3540 BC | 2850 BC | 308 | 1535 AD | 1764 AD | 1857 AD | 1907 AD | |||
| 28 | 3460 BC | 2650 BC | 312 | 1555 AD | 1772 AD | 1861 AD | 1911 AD | |||
| 32 | 3380 BC | 2450 BC | 316 | 1575 AD | 1780 AD | 1865 AD | 1915 AD | |||
| 36 | 3300 BC | 2250 BC | 320 | 1595 AD | 1788 AD | 1869 AD | 1919 AD | |||
| 40 | 3220 BC | 2050 BC | 324 | 1615 AD | 1796 AD | 1873 AD | 1923 AD | |||
| 44 | 3140 BC | 1850 BC | 328 | 1635 AD | 1804 AD | 1877 AD | 1927 AD | |||
| 48 | 3060 BC | 1650 BC | 332 | 1655 AD | 1812 AD | 1881 AD | 1931 AD | |||
| 52 | 2980 BC | 1450 BC | 336 | 1675 AD | 1820 AD | 1885 AD | 1935 AD | |||
| 56 | 2900 BC | 1250 BC | 340 | 1695 AD | 1828 AD | 1889 AD | 1939 AD | |||
| 60 | 2820 BC | 1050 BC | 344 | 1715 AD | 1836 AD | 1893 AD | 1943 AD | |||
| 64 | 2740 BC | 925 BC | 348 | 1735 AD | 1844 AD | 1897 AD | 1947 AD | |||
| 68 | 2660 BC | 825 BC | 352 | 1752 AD | 1851 AD | 1901 AD | 1951 AD | |||
| 72 | 2580 BC | 725 BC | 356 | 1760 AD | 1855 AD | 1905 AD | 1955 AD | |||
| 76 | 2500 BC | 625 BC | 360 | 1768 AD | 1859 AD | 1909 AD | 1959 AD | |||
| 80 | 2420 BC | 525 BC | 364 | 1776 AD | 1863 AD | 1913 AD | 1963 AD | |||
| 84 | 2340 BC | 425 BC | 368 | 1784 AD | 1867 AD | 1917 AD | 1967 AD | |||
| 88 | 2260 BC | 325 BC | 372 | 1792 AD | 1871 AD | 1921 AD | 1971 AD | |||
| 92 | 2180 BC | 225 BC | 376 | 1800 AD | 1875 AD | 1925 AD | 1975 AD | |||
| 96 | 2100 BC | 125 BC | 380 | 1808 AD | 1879 AD | 1929 AD | 1979 AD | |||
| 100 | 2020 BC | 25 BC | 384 | 1816 AD | 1883 AD | 1933 AD | 1983 AD | |||
| 104 | 1940 BC | 30 AD | 60 AD | 388 | 1824 AD | 1887 AD | 1937 AD | 1987 AD | ||
| 108 | 1860 BC | 70 AD | 140 AD | 392 | 1832 AD | 1891 AD | 1941 AD | 1991 AD | ||
| 112 | 1780 BC | 110 AD | 220 AD | 396 | 1840 AD | 1895 AD | 1945 AD | 1995 AD | ||
| 116 | 1700 BC | 150 AD | 300 AD | 400 | 1848 AD | 1899 AD | 1949 AD | 1999 AD | ||
| 120 | 1620 BC | 190 AD | 380 AD | 404 | 1853 AD | 1903 AD | 1953 AD | 2003 AD | ||
| 124 | 1540 BC | 230 AD | 460 AD | 408 | 1857 AD | 1907 AD | 1957 AD | 2007 AD | ||
| 128 | 1460 BC | 270 AD | 540 AD | 412 | 1861 AD | 1911 AD | 1961 AD | 2011 AD | ||
| 132 | 1380 BC | 310 AD | 620 AD | 416 | 1865 AD | 1915 AD | 1965 AD | 2013 AD | ||
| 136 | 1300 BC | 350 AD | 700 AD | 420 | 1869 AD | 1919 AD | 1969 AD | 2019 AD | ||
| 140 | 1220 BC | 390 AD | 780 AD | 424 | 1873 AD | 1923 AD | 1973 AD | — | ||
| 144 | 1140 BC | 430 AD | 860 AD | 428 | 1877 AD | 1927 AD | 1977 AD | |||
| 148 | 1060 BC | 470 AD | 940 AD | 432 | 1881 AD | 1931 AD | 1981 AD | |||
| 152 | 980 BC | 510 AD | 1010 AD | 1020 AD | 436 | 1885 AD | 1935 AD | 1985 AD | ||
| 156 | 900 BC | 550 AD | 1050 AD | 1100 AD | 440 | 1889 AD | 1939 AD | 1989 AD | ||
| 160 | 820 BC | 590 AD | 1090 AD | 1180 AD | 444 | 1893 AD | 1943 AD | 1993 AD | ||
| 164 | 740 BC | 630 AD | 1130 AD | 1260 AD | 448 | 1897 AD | 1947 AD | 1997 AD | ||
| 168 | 660 BC | 670 AD | 1170 AD | 1340 AD | 452 | 1901 AD | 1951 AD | 2001 AD | ||
| 172 | 580 BC | 710 AD | 1210 AD | 1420 AD | 456 | 1905 AD | 1955 AD | 2005 AD | ||
| 176 | 500 BC | 750 AD | 1250 AD | 1500 AD | 460 | 1909 AD | 1959 AD | 2009 AD | ||
| 180 | 420 BC | 790 AD | 1290 AD | 1540 AD | 464 | 1913 AD | 1963 AD | 2013 AD | ||
| 184 | 340 BC | 830 AD | 1330 AD | 1580 AD | 468 | 1917 AD | 1967 AD | 2017 AD | ||
| 188 | 260 BC | 870 AD | 1370 AD | 1620 AD | 472 | 1921 AD | 1971 AD | — | ||
| 192 | 180 BC | 910 AD | 1410 AD | 1660 AD | 476 | 1925 AD | 1975 AD | |||
| 196 | 100 BC | 950 AD | 1450 AD | 1700 AD | 480 | 1929 AD | 1979 AD | |||
| 200 | 20 BC | 990 AD | 1490 AD | 1740 AD | 484 | 1933 AD | 1983 AD | |||
| 204 | 60 AD | 1030 AD | 1515 AD | 1756 AD | 488 | 1937 AD | 1987 AD | |||
| 208 | 140 AD | 1070 AD | 1535 AD | 1764AD | 492 | 1941 AD | 1991 AD | |||
| 212 | 220 AD | 1110 AD | 1555 AD | 1772 AD | 496 | 1945 AD | 1995 AD | |||
| 216 | 300 AD | 1150 AD | 1575 AD | 1780 AD | 500 | 1949 AD | 1999 AD | |||
| 220 | 380 AD | 1190 AD | 1595 AD | 1788 AD | 504 | 1953 AD | 2003 AD | |||
| 224 | 460 AD | 1230 AD | 1615 AD | 1796 AD | 508 | 1957 AD | 2007 AD | |||
| 228 | 540 AD | 1270 AD | 1635 AD | 1804 AD | 512 | 1961 AD | 2011 AD | |||
| 232 | 620 AD | 1310 AD | 1655 AD | 1812 AD | 516 | 1965 AD | 2015 AD | |||
| 236 | 700 AD | 1350 AD | 1675 AD | 1820 AD | 520 | 1969 AD | 2019 AD | |||
| 240 | 780 AD | 1390 AD | 1695 AD | 1828 AD | 524 | 1973 AD | — | |||
| 244 | 860 AD | 1430 AD | 1715 AD | 1836 AD | 528 | 1977 AD | ||||
| 248 | 940 AD | 1470 AD | 1735 AD | 1844 AD | 532 | 1981 AD | ||||
| 252 | 1010 AD | 1505 AD | 1752 AD | 1851 AD | 536 | 1985 AD | ||||
| 256 | 1050 AD | 1525 AD | 1760 AD | 1855 AD | 540 | 1989 AD | ||||
| 260 | 1090 AD | 1545 AD | 1768 AD | 1859 AD | 544 | 1993 AD | ||||
| 264 | 1130 AD | 1565 AD | 1776 AD | 1863 AD | 548 | 1997 AD | ||||
| 268 | 1170 AD | 1585 AD | 1784 AD | 1867 AD | 552 | 2001 AD | ||||
| 272 | 1210 AD | 1605 AD | 1792 AD | 1871 AD | 556 | 2005 AD | ||||
| 276 | 1250 AD | 1625 AD | 1800 AD | 1875 AD | 560 | 2009 AD | ||||
| 280 | 1290 AD | 1645 AD | 1808 AD | 1879 AD | 564 | 2013 AD | ||||
| 284 | 1330 AD | 1665 AD | 1816 AD | 1883 AD | 568 | 2017 AD | ||||
| From | To | Add |
|---|---|---|
| -4000 BC | 1000 AD | 20 years |
| 1000 AD | 1500 AD | 10 years |
| 1500 AD | 1750 AD | 5 years |
| 1750 AD | 1848 AD | 2 years |
| 1848 AD | 2020 AD | 1 year |
See also[]
- Turn (Civ1)
- Turn (Civ2)
External links[]
- "Gov't Change, Super Science City, & Super Growth – CivFanatics War Academy article on oedo years. N.B.: Link to PDF chart is depreciated.
Footnotes[]
- ↑ A bug in Civ1 allows anarchy to be reliably avoided: when loading a game on an oedo year, any ongoing anarchy is immediately resolved. Thus, instigating a revolution, saving, then loading the game results in a "zero-turn" revolution.[2]: post 28
- ↑ "The Barbarian Paper" by William Keenan claims barbarians in Civ2 begin spawning on the 16th turn (4th oedo year), however this is only true at Deity: lower difficulties spawn later.
- ↑ See tupi's documentation of the Civ1 game code:[3]: post 21 chance for a land-based uprising is calculated every turn.
- ↑ The Civilization II MGE User Interface Additions mod adds turn count to the Status window in the Multiplayer Gold Edition.
References[]
- ↑ 1.0 1.1 1.2 1.3 oedo (12 February 2001). "Oedo years - I think this should be common knowledge". Civilization Fanatics' Center. Retrieved 9 September 2023.
- ↑ 2.0 2.1 Valen (28 June 2008). "RE: What Wonders do you Hate? (Be Inflammatory!)". Civilization Fanatics' Center. Retrieved 9 September 2023.
- ↑ 3.0 3.1 SWY (18 March 2018). "Barbarians spawn logic". Civilization Fanatics' Center. Retrieved 9 September 2023.
- ↑ stwils (27 June 2006). "RE: How many turns in a game?". Civilization Fanatics' Center. Retrieved 9 September 2023.