View source for Commander Keen: Secret of the Oracle

Commander Keen Episode 4: Secret of the Oracle (or simply Keen 4) was developed by iD Software and published primarily by Apogee Software. It is the first of two episodes in the "Goodbye, Galaxy!" series of games (the other being [[Commander Keen: The Armageddon Machine|Keen 5]]) and was distributed as shareware. It follows Keen through an adventure to the planet Gnosticus IV, where he must rescue the High Council of the Oracle within the treacherous depths of the Shadowlands. It is the longest any% run in the entire Commander Keen series, with very few glitches to save time and a supreme reliance on execution, anticipation, and a little luck. It is also one of the most contested records in the series, with the best time switching between several runners over the course of a couple years.

== Overview ==

In order to win the game, Keen must find and rescue all eight members of the High Council (hereafter known as "Oracles" as is the slang of these characters) scattered throughout the game, which makes for eight individual levels. Besides this, three additional levels are required to access levels occupied by Oracles. This makes for a total of eleven levels.

For the most part, each of the eleven levels must be completed in full. While there are means to [[Commander Keen: Galaxy#Exiting Out of Bounds|exiting levels early]], gatherable components (such as the swimming gear and the Oracles themselves) will not be flagged as acquired unless directly touched. Note also that such items in this game cannot be touched using the [[Commander Keen: Galaxy#Death No-Clip|death-exit glitch]], either (though even if it could there are very few instances in which it would be useful in the run). Thus, a great deal of the run has been focused on optimizing the route through each level and executing said optimizations as flawlessly as possible.

=== Categories ===

Generally, this game is played using version 1.0 shareware. Version 1.0 has a slightly different ledge-climbing end state that provides a better setup for certain jumps, and shareware is the most widely available distribution of the game. Although this is often what runners of the game use, if another version is proven to be faster it may be considered acceptable (if the time difference is significant enough).

The '''any%''' run is played on Normal difficulty: this is needed in order to add an enemy in one level to finish it using the death-exit glitch about twenty seconds faster. Playing on Easy difficulty adds no shortcuts to the run, while Hard only makes the game more luck-reliant, so Normal is considered the fastest difficulty from which to approach the game.

The '''100%''' run of this game is defined as having completed all levels, regardless of order, in addition to completing the game according to its intended objective. This includes completing the secret level, which is only known to be accessible through a secret exit from another level (finishing said level through its secret exit completes it).

== Glitches ==

This section addresses game-specific glitches only. For glitches spanning the entire Galaxy set of games, check the [[Commander Keen: Galaxy#Glitches|Galaxy engine page]]. Similarly, are glitches specific to a level are addressed in the appropriate section.

=== Exit Sound Override ===

When entering and exiting levels, a brief jingle is played: interestingly, it is considered a sound effect by the game, rather than a music track. Furthermore, there are a limited number of sound effects that can be played concurrently, such that if some sound effects are currently playing, other sound effects will ignored until the first has finished. The combinatory consequence of these engine quirks is that you can override the exit sound with another in order to exit the level slightly faster. (This cannot be done with the entrance sound because there are no sound effects producible from the map that would properly cause this override.)

The most commonly sound effect used to override the exit level jingle is the sound played when pressing the Enter key to access the score/inventory menu. To perform this override using this menu:

# Get very close to the exit (within a Keen width)
# Open and immediately close the menu
# Exit the level

If executed properly, Keen will exit the level without the jingle. (Alternatively you could pogo into the exit, so you don't have to worry about movement after you close the menu.) As the menu takes time to open and close, this isn't a large time-saver, but it will save as much as half of a second per use. Other known sounds that override the jingle are the 1UP sound and the item-get sound (such as the one from the swimsuit, although it does not actually work for the swimsuit since time is stopped when played there).

=== Faster Bouncing ===

Reloading the game while bouncing creatures (Bounders, Mad Mushrooms) are on the screen will occasionally cause their bouncing oscillation to speed up. Similarly, reloading when this bouncing is faster may restore their oscillation to normal speeds.

There is no known use for this glitch in speedrunning.

=== Bounder Leap ===

Most enemies have a very specific momentum when jumping or bouncing and tend to ignore the normal considerations of gravity when doing so. However, when Keen defeats such an enemy in mid-jump, their momentum acts under normal gravity, allowing for the possibility of their corpse to experience an especially high (or long) flight. In the case of the Bounder, on whom Keen can stand, it is possible to use this extra-high jump to reach places otherwise unreachable.

There is no known use for this glitch in speedrunning.