Beetlejuice (NES)/Game Mechanics and Techniques

Scares

Name	Cost	Shots	Special ability	Comments
Medusa head	100	1	Freezes "floating skulls" (found in some bug holes)
Birdman	150	2	Increases jump height	The jump ability allows for shortcuts and is very useful in a speedrun
Two-headed man	200	3	1-hit kills the sandworm on Saturn
Skeleton	250	5	No damage from bees, 1-hit kills the beehives (both only found in level 1)
Umbrella head	400	9	None?	The manual hints about giving some sort of advantage against the octopuses in the sewer stage
Ogre	500	12	1-hit kills the cavern monsters in level 2 (Storm drains)
Ghost (called "spooksheet" in the game)	600	15	None?	Only available in the graveyard level. The manual does not seem to hint about any special ability. It sounds more like it's an "all-purpose" scare with lots of shots.
Snakeman	750	19	None?	Same comments as for the ghost scare.

RNG

The RNG-addresses in RAM are $24-$27. They're calculated by various operations between themselves and take the result of the previous set of RNG and the global timer ($3BB) as seeds.

The RNG-function is called by various events that require a new set of RNG. This can result in the RNG being calculated from several times per frame to every few frames or not all (if nothing loaded in memory requires RNG-values.

There is no indication that the RNG-values would be possible to manipulate in real-time. In TAS-conditions, the RNG can be manipulated to a certain extent by performing actions that trigger the RNG-function to be called. Beetlejuice's movements don't impact the RNG-function, but e.g. throwing a potion (in the overhead section) will create additional calls of the RNG-function.