- Blessed: 160–169 turns
- Uncursed: 100–109 turns
- Cursed: 40–49 turns
If you are already very fast you will be told “Your legs get new energy.” If the potion is shattered and you are exposed to the vapors, it will give you 1-5 turns of very fast speed and the message “Your knees seem more flexible now.” You can then name the potion. Quaffing this potion also heals wounded legs.
If you decide to swap your speed boots for jumping boots on the Astral Plane, a potion of speed will allow you to remain very fast. This is particularly useful if you are also using a wand of teleportation, because it increases your chances of being able to jump through the path you have cleared before monsters can reoccupy it.
Potions of speed are also useful for upgrading potions of healing to potions of extra healing via alchemy. Using a speed potion for this allows you to save your potions of gain level and gain energy for other purposes.
Beyond these two uses, potions of speed are not considered especially valuable and are good candidates for dilution.