TomeNET

(4.11a) Drain effects                                                           
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Apart from the effects listed above which are indicated in the status bar at
the bottom of the main window, there are three 'drain' effects that can be
caused by items and three other 'drain' effects that can be caused by monsters,
traps or elemental attacks you suffer (possibly from terrain too).


Drain effects caused by items:
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Experience drain ('Drains your life force')
    Having 'Hold Life' does not protect against this.
    Having 'Keep Life' (only obtainable from either having both Necromancy
    and Unlife maxed out at 50.000, or from attaining character level 99)
    completely prevents any XP drain, always, including drain from items.

    If you equip multiple items that drain experience, the total drain will
    diminish with each further item though instead of adding up, so for example
    using two rings of power will be less severe than than one might expect.
    If experience drain hits the threshold for your current character level, it
    will not drain any further, so you cannot lose a level from it. Beware
    however, that you are not hit by another life draining effect that lowers
    your experience further below the level threshold, or the experience drain
    will kick in again.
    While the player is on the world surface, the effect is lessened compared
    to being inside a dungeon/tower.
    Experience drain is on hold while you are in town areas, this includes
    dungeon towns.
    Having an anti-magic field will further reduce the frequency of draining
    by half of the anti-magic field strength (75% / 2 = 37.5% slower drain).
    All the rings of power that are dropped by Nazgul drain experience (and
    turn you invisible). Note that having multiple items that drain experience
    will not result in a linear increase of the drained amount. Instead, each
    further draining item will drain less, making it more feasible for exampe
    to equip two rings of power.
    The higher the experience gain ratio of a character is (depending on its
    race/class combination) the worse it will be hit by experience drain from
    items, with Maiar being the class that has the most trouble compensating.
    Vampire race characters suffer half as much from exp drain as anyone else.

Mana drain ('Drains your magic')
    Drains your mana pool over time while you have this item equipped.
    Can be countered if your MP regeneration happens to be faster than the
    drain. Multiple items draining mana will stack linearly.
    Warriors and archers are not affected as they don't have any MP.

Hit point drain ('Drains your hit points')
    Drains your hit points down to zero, then stops. This means that this
    effect won't kill you, but can make it extremely risky to go AFK in an
    unsafe place, as any further damage you suffer from whatever reason would
    finish you off. Well, going AFK in an unsafe place can kill you anyway.

    HP drain stacks linearly and is given by:
     -Items that just drain your HP
     -Items that have strong good powers and you use them as a Vampire
     -The sun, when it's day and you're a Vampire and out in the open without
      a protective wrapping, such as a Mummy Wrapping, or something granting
      resistance to light.
     -Monster forms that provide wall-passing (wraith form)

    HP drain can be countered by HP regeneration, which can be gained from:
     -'Regeneration' ability (which is a flag, ie one source providing it is
      enough and having more than one regen source won't increase the effect),
      gained from items or as racial/form bonus
     -Health skill
     -Holy Curing school bonus
     -Nature school spell
     -Biofeedback from fire stones
    which all stack too.

    Note that vampire race characters are immune to specifically the DRAIN_HP
    effect on 'Spectral' ego weapons.

Also see (5.15) for how these drain effects stack or may be cancelled out.


Drain effects caused by monsters, traps or elemental attacks including terrain:
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Experience drain from monster attacks, traps or elemental damage you suffer
    'You feel your life draining away!' - the normal message.
    'You feel your life slipping away!' - you suffer less drain, happens if you
                                          acquired the 'Hold life' power, which
                                          is the specific resistance meant to
                                          counter experience drain.
    'You keep hold of your life force!' - you suffer no drain! Happens if you
                                          have 'Hold life' and get lucky.
    'You are unaffected!'               - you are completely unaffected by
                                          experience drain ('Keep life').
                                          To acquire this ability you need to
                                          be either level 99 or have Necromancy
                                          and Unlife skill both maxed out at
                                          50.000.
    Some of your experience points will be drained. If this happens a lot, you
    might even lose one or more character levels! (You retain all your skill
    points though.)
    When your experience is drained this way, it will be displayed in yellow
    colour instead of light green on your character sheet (SHIFT+C) and in your
    'XP' bar on the main screen.
    The game remembers your original amount of experience though and you can
    restore it by purchasing a potion of 'Restore Life Levels' from the temple
    in town or by corresponding restoration magic of various sorts.
    It is recommended to restore your experience ASAP because any further gain
    of experience points while in drained state will only count towards your
    original maximum by 10% of its real value, resulting in large amounts of XP
    being wasted. (Example: Your XP gets drained from 2000 to 1500, you kill a
    monster that gives 100 XP, now you have 1600 of 2010 XP.)

Experience drain from Black Breath
    This is especially nasty as being infected with Black Breath will drain
    experience permanently instead of temporarily.

Stat drain
    This type of drain will lower your atttributes, which can be:
    STR (strength), INT (intelligence), WIS (wisdom), DEX (dexterity),
    CON (constitution) and CHR (charisma).
    While drained, these will be displayed in yellow colour instead of light
    green on your character sheet (SHIFT+C) and in your 'XP' bar on the main
    screen.
    The game remembers your original stats though and you can restore any stat
    by purchasing a potion of 'Restore <stat name>' from the alchemy shop in
    town or by corresponding restoration magic of various sorts.

    Note however that there are three tiers of stat drain:
    I:   Temporary drain. Low-level traps will often do this. Also this might
         happen to your strength stat if you overexert yourself at swimming.
         You can just sit it out and after some time it will automatically
         restore itself back to normal (colour changes from yellow to light
         green again accordingly).
    II:  Persistent drain. Medium level traps, monster attacks and certain
         elemental damage you suffer can cause this.
         Again the drained stat will be displayed in yellow, but unlike tier I
         drain it will not self-restore. Instead you will need to purchase a
         potion from the alchemy shop or use other means of restoration magic.
    III: Permanent drain. High level traps are the only way to suffer this.
         Your stat will actually not turn yellow, but remain light green and
         its reduction cannot be undone by restoration magic!
         The only way to counter this is by finding stat potions. These in turn
         permanently increase a stat. So high-level characters might want to
         always keep some of those potions in reserve even if they already
         maxed out a stat.

    It is especially nasty when your primary stats are drained. For a melee
    fighter these are usually STR and DEX, as these determine your attack speed
    aka BpR (blows per round). If you suffer stat drain here and notice that
    your BpR just dropped for example from 3 to 2, it means you just lost
    33% of your attack power! So you might want to return to town immediately
    to restore the affected stats.
    For a magic user it might be INT or WIS, depending on the type of magic
    they use. If these get drained it will not only reduce their mana pool
    (MP) but also increase the fail rates of their spells, so again you might
    want to restore your primary stats as soon as possible.
    Note that WIS drain can under certain circumstances be especially nasty as
    WIS is the stat that mostly determines your sanity pool. So if you are
    planning to fight a monster that can drain your sanity, make sure your WIS
    stat is fully restored before you engage.

    Notes:
    - 'Sustenance' powers will help to prevent all three tiers of stat drain!
    - Drinking a stat potion will automatically restore your stat if it was
      drained, before permanently increasing it. So you don't need to purchase
      an extra restoration potion before drinking a stat potion.
    - If you are infected with Black Breath, it can also drain your stats
      randomly (yellow aka tier II kind of drain).
    - While items cannot drain stats in general, there is one single exception:
      If an item possesses the 'TY_CURSE', a special, strong curse (see (5.12))
      this curse can cause a tier II drain (aka yellow stat colour).

Sanity drain
    The most dangerous drain effect of all.
    Some traps can cause this, drinking too much booze might also do its share
    but mostly it will be from monster attacks, which can be ranged psychic
    attacks as well as certain melee attacks.
    If your sanity (see 'SN' indicator in the main window) gets drained too far
    you will start hallucinating and if it reaches zero you will turn into an
    unthinking vegetable, effectively erasing your character even if it is
    'everlasting' mode and without any way of resurrecting!
    So never let your character run out of sanity or it will die permanently!

    Fortunately there are potions (and certain curing magic) to restore sanity,
    albeit they cannot be purchased in normal stores.
    See (7.6) for more information about sanity.