I'm planning to add in-game low% leaderboards during early access. (If there's a lot of demand, I could put some up here in the meantime.)

Yeah, as mayantics says, people don't really play those characters low%. The reason why is that the characters listed (Dove, Aria, Melody, Bolt, Eli) have the most fun & interesting low% play.

Replays basically just remember which inputs you made, and when you play the replay, the game replays those inputs. Because it's the same inputs you made, usually the run is the same, but because of bugs, sometimes it isn't.

That's partly why, for these boards, submissions require original run videos (not replays): http://www.speedrun.com/Crypt_of_the_NecroDancer/thread/d7f7j

Submitted runs should be unseeded. If you're competing on the leaderboard, play unseeded.

However, a seeded run may be accepted at discretion if:

• the run occurred in a competition using random seeds
• the player couldn't have got useful information by screen-watching, because of being ahead the whole race
• it's sufficiently far off WR contention (to avoid controversy)

These conditions apply to mudjoe2's Aria Low% run.

Currently the policy is to accept only videos of the original run, not a replay. There was a discussion on the Necrodancer Discord about this some time ago.

The core reason is that a replay is only an unreliable reconstruction of the original run.

This creates a variety of specific problems, but the biggest one is: if you are running a low% category without video-recording your runs and get a PB, sometimes the replay will desync. Then you wouldn't be able to submit your PB even if replays were accepted. So to avoid randomly losing PBs, it's better to video record all your runs if you are running a category seriously.

A secondary reason is that the time reported at the end of a replay is just a number stored as text in the replay file. As such it is easy to modify. The replay timer is inaccurate anyway so detecting a small modification would be impossible.

The official Steam leaderboard is viewable in-game and is mirrored on the web at http://crypt.toofz.com/leaderboards .

There is also an official leaderboard for the GOG.com release. As far as I am aware, it is only viewable in-game by those who have purchased that version and is not viewable on the web.