Super Mario Bros. level reuse

There are four official Mario games using the original Super Mario Bros. engine (at least that I know about, and aside from remakes that keep the order of levels the same), which reuse levels from themselves and each other in various ways:

  1. Super Mario Bros. has eight worlds with four levels each. However, starting with 5-3, some levels are harder versions of previous levels. These harder versions use the same level data in the ROM, but some enemies have a flag set that makes them only appear if the level is at least 5-3, and some things have code to check if the level is at least 5-3 and behave differently if it is (e.g. all moving platforms will be shorter).
  2. The arcade game VS. Super Mario Bros. is mostly the same as the original, but it moves some levels around and replaces the repeat levels (and 3-2) with new levels.
  3. The originally Japanese-exclusive Super Mario Bros. 2, which was later released elsewhere as Super Mario Bros.: The Lost Levels, is mostly new levels, but it does reuse all of the new levels that were added to the VS. version. In addition to the main 8 worlds, there's an extra world 9, which is accessed by beating every world in the game (no warp zones), and A through D, which are accessed by completing the main game 8 times. While the game mostly doesn't repeat its own levels, C-3 and C-4 are slightly-modified copies of 7-3 and 7-4, though they don't share data in the ROM like Super Mario Bros.'s repeats do.
  4. There's also All Night Nippon Super Mario Bros., which has the levels from Super Mario Bros. but the graphics and I think game engine from Lost Levels. Like VS., it replaces duplicate levels (and 8-4) with different levels, but does so differently than VS. does (but it doesn't have its own new levels, just reuses ones from VS. and Lost Levels). It also has worlds A through D, like Lost Levels.

The following table shows which levels were reused where:

SMBVS.LLANN
1-1SMB 1-1SMB 1-1LL 1-1SMB 1-1
1-2SMB 1-2SMB 1-2LL 1-2SMB 1-2
1-3SMB 1-3SMB 1-3LL 1-3SMB 1-3
1-4SMB 1-4VS 1-4VS 1-4SMB 1-4
2-1SMB 2-1SMB 2-1LL 2-1SMB 2-1
2-2SMB 2-2SMB 2-2VS 3-2SMB 2-2
2-3SMB 2-3SMB 2-3LL 2-3SMB 2-3
2-4SMB 2-4SMB 1-4LL 2-4SMB 2-4
3-1SMB 3-1SMB 3-1LL 3-1SMB 3-1
3-2SMB 3-2VS 3-2LL 3-2SMB 3-2
3-3SMB 3-3SMB 3-3LL 3-3SMB 3-3
3-4SMB 3-4SMB 3-4LL 3-4SMB 3-4
4-1SMB 4-1SMB 4-1LL 4-1SMB 4-1
4-2SMB 4-2SMB 4-2LL 4-2SMB 4-2
4-3SMB 4-3SMB 4-3VS 6-3SMB 4-3
4-4SMB 4-4SMB 2-4LL 4-4SMB 4-4
5-1SMB 5-1SMB 5-1LL 5-1SMB 5-1
5-2SMB 5-2SMB 5-2LL 5-2SMB 5-2
5-3SMB 1-3SMB 6-3LL 5-3VS 6-3
5-4SMB 2-4SMB 4-4VS 6-4LL 2-4
6-1SMB 6-1SMB 6-1LL 6-1SMB 6-1
6-2SMB 6-2SMB 6-2VS 7-2SMB 6-2
6-3SMB 6-3VS 6-3VS 7-3SMB 6-3
6-4SMB 1-4VS 6-4LL 6-4LL 4-4
7-1SMB 7-1SMB 7-1LL 7-1SMB 7-1
7-2SMB 2-2VS 7-2LL 7-2VS 7-2
7-3SMB 2-3VS 7-3LL 7-3VS 7-3
7-4SMB 7-4SMB 7-4LL 7-4SMB 7-4
8-1SMB 8-1SMB 8-1LL 8-1SMB 8-1
8-2SMB 8-2SMB 8-2LL 8-2SMB 8-2
8-3SMB 8-3SMB 8-3LL 8-3SMB 8-3
8-4SMB 8-4SMB 8-4LL 8-4LL 8-4
9-1LL 9-1
9-2LL 9-2
9-3LL 9-3
9-4LL 9-4
A-1LL A-1LL A-1
A-2LL A-2LL A-2
A-3LL A-3LL A-3
A-4LL A-4LL A-4
B-1LL B-1LL 5-1
B-2LL B-2LL B-2
B-3LL B-3LL 3-3
B-4LL B-4LL B-4
C-1LL C-1LL C-1
C-2LL C-2LL C-2
C-3LL 7-3LL 7-3
C-4LL 7-4LL 7-4
D-1LL D-1LL 8-1
D-2LL D-2LL D-2
D-3LL D-3LL D-3
D-4LL D-4LL D-4

You can find more information in this Retro Game Mechanics Explained article, which is my source for this information. I'm mainly posting this to show the chart I made in response to that post, which I posted as a response on Cohost:

A chart showing the same information as the table above.

Two levels connected = same level reused. Organized by the level number within a world (so all the x-1 levels are together, etc.) because all of the duplicates have that number the same.

A couple other random facts about this: