Movement Speed

The movement speed of a character is determined mostly determined by three parts: There's three additional modifiers applied later: The final movement speed of a character is
 * 1) The body stats
 * 2) Movement speed increases
 * 3) Movement speed slows
 * 1) The stacking debuff from the floating bugs created by the Beetle Queen. This is called the BeetleJuice Debuff. This is equal to.
 * 2) If a character is weakened by REX, their movement speed is multiplied by 0.6.
 * 3) The Spinel Tonic gives either a buff, or depending on the affliction count, a debuff.
 * 4) If the Tonic is active, the movement speed is multiplied by 1.3
 * 5) Otherwise, the movement speed is multiplied by

Body Stats
The body stats of a character are the base movement speed (7 for all Survivors) plus the level movement speed (0 for all Characters). All of this is increased by the sprint multiplier if the character is sprinting. As of writing, only player characters sprint. The sprint multiplier is 1.45 or +45%.

Increases
The increase multiplier starts at 1 increased by various values, listed below.

The following movement speed increases exist:
 * Red Whips, which give 0.3 + 0.3 per stack
 * Paul's Goat Hoof, which give 0.14 + 0.14 per stack
 * Energy Drink, which give 0.207 + 0.138 per stack.
 * If the Milky Chrysalis is active, it gives 0.2.
 * If the character is in range of any amount of friendly Warbanners, they get 0.3.
 * If the character is cloaked by the Old War Stealthkit, they get 0.4.
 * If the character has the Berzerker's Pauldron's buff they get 0.5.
 * [UNUSED] There's an unused ability called "EngiTeamShield", which gives 0.3 to friendly characters in radius. Note that this is a different shield that the Engineer normally has.
 * [UNRELEASED] The Ancient Wisp can enrage, giving it 0.4 to this multiplier.

Decreases
The decrease multiplier starts at 1 and is increased by various values listed below.

The following movement speed decreases exist:
 * If a character was hit recently by the Chronobauble, this modifier is increased by 0.6.
 * If a character was hit recently by Runald's Band or by an attack from a Glacial Elite (including characters who got it from Wake of Vultures or Her Biting Embrace), this modifier is increased by 0.8.
 * The pots in the Abandoned Aqueduct and from the Clay Dunestrider, going outside of bounds in the Abandoned Aqueduct, jumping through the waterfall (or rather clay goo fall) in the Aqueduct, and the boop from Clay Templar all apply the ClayGoo debuff, which increase the modifier by 0.5.
 * The Effigy of Grief increases this modifier by 1 if the character is in its area of effect.
 * [UNUSED] and [UNRELEASED] If the Sniper is scoped in, or a character is hit by the Engineer's turret alternative that fires a laser, this modifier is increased by 0.5.
 * [UNUSED] There's an unused debuff that increases this modifier by 0.3.