This feature provides API for two things - potion effects and potions themselves. To this end, it introduces two main classes - Potion and PotionEffect. A potion effect has a duration (measured in ticks) an amplifier, and a PotionEffectType, and can be applied to LivingEntities, causing effects such as blindness, faster moving speed, and more. Amplifiers increase the strength of an effect and are effect-dependent, such as how much health will be given by the heal effect. Various methods exist in LivingEntity to give effects, such as Code: LivingEntity.addPotionEffect(PotionEffect) and LivingEntity.getActivePotionEffects() Note that only one potion effect of a given type can be present at any one time, and that the potion effects NIGHT_VISION and INVISIBILITY are unusable due to not being implemented by Minecraft. The Potion class acts as a representation of an ingame potion, and can be created using Code: new Potion(PotionType); where PotionType is an enum of the usable subset of potion effects. Potions have a tier (accessible using the Potion.Tier enum) which alters the amplifier of the resulting effect, an 'extended duration' flag, which increases duration by a set amount (roughly 8/3 * base duration), and a splash flag, which allows the potion to be thrown and affect an area. Potions can be created from a raw damage value using the static methods Code: Potion.fromDamage(int) and Potion.fromItemStack(ItemStack) and applied to both LivingEntities (by adding the effects of the potion) and ItemStacks (by setting the raw damage value). Finally, the Potion class also contains a PotionBrewer (Potion.getPotionBrewer()), which contains two small helper methods, used to convert from raw potion damage values to PotionEffects, and to create PotionEffects with modifiers from PotionEffectType applied.
