|This spell extends the duration of most beneficial enchantments affecting the caster.|
Extension was a level 5 Enchantments spell which extended the duration of certain enchantments affecting the caster. It also had a 50% chance of causing one point of magic contamination (plus an extra guaranteed point if extending Haste or Invisibility).
You could not extend spells you hadn't memorized, or extend non-spell effects such as Might. The chance of extending a spell was 50% + the spell's success rate, meaning you could fail to extend spells with a spell success level of "Poor" or below.
Extension prolonged the following magical effects already affecting you as if you had just recast that enchantment at the same spell power as your Extension spell, with the exception of Ring of Flames and Condensation Shield.
100 turns maximum:
- Bat Form if not a vampire (min 0)
- Blade Hands (min 0)
- Deflect Missiles (min 15)
- Dragon Form (min 0)
- Flight (min 25, double extension)
- Ice Form (min 0)
- Insulation (min 10)
- Invisibility* (min 0)
- Levitation (min 25)
- Necromutation (min 0)
- Regeneration (min 5, 2/3 extension)
- Repel Missiles (min 8, double extension)
- Resist Poison (min 10)
- See Invisible (min 10, half extension) - no expiration warning!
- Silence (min 10, average of two extensions) (note in source: "how precisely did you cast extension?")
- Spider Form (min 0)
- Statue Form (min 0)
- Stonemail (min 20, double extension)
- Swiftness (min 20)
80 turns maximum:
- Haste* (min 40, 100 turns maximum if wearing an amulet of resist slowing)
50 turns maximum (you will usually see the expiration messages of these):
- Control Teleport (min 10)
- Ozocubu's Armour (min 20, double extension)
- Stoneskin (min 10, double extension)
30 turns maximum:
- Phase Shift (min 5)
Extended only by a few turns:
- Condensation Shield (max 30)
- Ring of Flames, extended only a few turns, randomly up to power/20, thus usually around 5 and at most 20 (max 50)
- Any temporary weapon brand spell currently in force
For each of the asterisked effects that are prolonged, you gained one point of magic contamination instantly. This is in addition to the 50%-likely single point of magic contamination you might have incurred anyway AND the ongoing magic contamination due to Invisibility or Haste being in effect.
Extending Phase Shift was problematic because it has a cap of 30 and a warning about 5/6 turns before expiration, and Extension caused 0.5 glow, while you only lose 0.5 glow every 20 turns. At power 100, Extension would set the Phase Shift turns to about 25 on average. Thus, you had to wait some turns after the warning to extend, and even then, the thin margins often lead to mutagenic glow.
You could use this spell to keep several effects on indefinitely without needing to repeatedly recast the individual spells. This saved time and MP in battle and while travelling, and was a general convenience to the player.
As an example, the following set could be sustained indefinitely, if you had the individual spells memorised:
- Ozocubu's Armour
- Resist Poison
- Control Teleport
- Deflect Missiles
Adding Necromutation obviates the need for Resist Poison and disables Stoneskin, and Regeneration:
Casting Necromutation will result in excommunication by good gods, and reliably extending it requires fairly high skill in Necromancy and Transmutation (15+). Its benefits more than offset its disadvantages, however.
To get the most out of Extension, you should change your game configuration to inform you when you need to recast the spell.
Add the following lines to your init.txt. They will cause the game to stop when your spell effects are about to expire.
travel_stop_message = duration: force_more_message = duration: travel_stop_message = You are starting to lose your buoyancy force_more_message = You are starting to lose your buoyancy travel_stop_message = You have a feeling this form force_more_message = You have a feeling this form message_colour = lightred:You have a feeling this form travel_stop_message = Your transformation force_more_message = Your transformation message_colour = lightred:Your transformation travel_stop_message = You feel uncertain force_more_message = You feel uncertain travel_stop_message = Your deflect missiles force_more_message = Your deflect missiles
Then, adjust the extension spell to a letter you like (for instance 'z' so you tap 'zz') and/or add a macro for it.
After that, whenever you get a duration message, dismiss the --More-- prompt and cast Extension.
Occasionally a spell will only be extended for a few turns or even one turn, so if you get any kind of expiration message immediately after casting Extension, cast it again.
It is a good idea to wield a staff of enchantments when you are traveling or doing non-combat activities so that your extensions will last longer.
It is possible to use Haste while also using Extension, although you do not want to cast Extension while you are hasted, as this will soon lead to mutagenic levels of magical contamination.
One way to safely combine the two spells is to cast Extension with a staff of enchantments wielded, ideally multiple times (so that your enchantments last more than 80 turns, the maximum of Haste). Then, cast then Haste itself (which will be in force for 40-80 turns). You may also want to wield a lantern of shadows, to increase the chances of Haste taking less than 50 turns, so that it expires before Ozocubu's Armour and Control Teleport.
A simpler method is to re-cast any individual spells that expire before Haste does; once Haste itself expires, you can safely cast Extension again if you are not already substantially contaminated.
Should you find yourself glowing as a result of accidentally extending Haste, make certain to not extend it again. An amulet of resist mutation will ward off mutation 90% of the time; if playing as an undead (or if necromutated), you will rot instead of mutating, which can be cured via the means outlined on the rot page.
If you want to turn invisible, use a ring of invisibility or cloak of darkness to turn visible when no longer needed.
Extension was removed in 0.8.