I am noticing this tag get misused.
The big ones I"m seeing are:
1) Confusing hard to achieve ACE circumstances with manipulating randomness.
[2601] NES Mega Man "game end glitch" by pirohiko & finalfighter in 00:32.11 is not luck manipulation, nor
[2513] SNES Super Mario World "arbitrary code execution" by Masterjun in 02:25.19. These movies create events very unlikely to be encountered in normal play. But they do this with precise exploitation of overflowing memory values and causing ram (that was precisely manipulated to specific values) to be run as code. No RNG is involved in this.
2) Deciding that
any manipulation of luck means to tag it with "Heavy Luck Manipulation". Just because they get 1 favorable drop from an enemy, this is not heavy luck manipulation
3) Worse yet, if the
submission simply says "Manipulates Luck", I'm seeing the judge/publisher blindly apply this tag. What was manipulated? Where? How is it a big aspect to the movie?
How to use this Tag correctly:
1) The intent of this tag is firstly to identify runs that manipulate random events. Pretty much, there must be an RNG involved. If you don't manipulate an RNG, this tag doesn't not apply
2) The events must be UNLIKELY, very unlikely, beyond anything a human could hope and plan for, in a speedrun. Good examples are unlikely drops by enemies, critical hits, and unlikely RPG events (again critical hits, or enemies missing, or running away).
3) Luck manipulation must be a significant aspect to the TAS, throughout. A good example is movie
[2455] GBA Castlevania: Harmony of Dissonance "Simon, Boss Rush, Hard" by Robert_Ordis in 07:51.27, a TAS that makes use of critical hits on all major enemies. Or
[951] NES Darkwing Duck by AnS, Randil in 10:59.50 that constantly depends on unlikely enemy drops throughout
4) The "lucky" moments must be apparent to the user. Again, critical hits are easy to see, constant enemy drops. Or just obviously getting really lucky (
[2425] SNES Vegas Stakes by hero of the day in 02:43.20) in a game of chance
Obviously the most common types of TAS that qualify well with this tag are RPG's (think Dragon Warrior, Final Fantasy, Pokemon). But not always. As already linked, games like Darkwing Duck and Castlevania II (drops), Symphony of the Night and Harmony of Dissonance (critical hits) are great examples as well.
In summary, publishers, and judges need to be more careful about applying this tag, and think through the situation more. Don't be afraid to get clarification from an author if they suggest this tag without elaborating why (and it isn't obvious from the movie).