Spell Interpretations  Spells are as given in the AD&D Players Handbook (1st ed.), with the following interpretations:

    RANGE or AREA:        1" => 10ft 
    DURATION:                 Segments => Rounds;  Rounds => Minutes.
    CASTING:                     Under 1 Segment => Free action;  Under 1 Round => Standard action; 1 Round => Full Round action
    CASTER LEVEL:          For Range, Duration & Damage => Spell Power;  For Area & Other Effects => 2 x Spell Power
    SAVING THROWS:     STAT x 5 (e.g. DEX x 5 v damaging physical effects; WIS+Modifier x 5 v mental attacks/enchantments)

These other translations are also required for a few odd spells:
    TO HIT modifier:          +1 To Hit => +1 Damage;  -1 To Hit => -1 Damage.
    ARMOUR CLASS:       1 AC Place => 1 Armour Point (AP).
    MOVE:                           12" = 10squares (translate pro-rata, e.g. 6" = 5sq).
    EFFECT per HD:           HD => HP/5  or  LEVEL (i.e. Defence/10), whichever is greater.
    EFFECT per HP:            Use HP  or  DEFENCE%, whichever is greater.
    FIGHTING SKILL:        20% + 10% per Fighter LEVEL or Monster HD.

Spell Modifications  The following spells have these notable modifications from the standard PHB versions:
Suggestion: 1st Level (not 3rd).
Charm Person: 2nd Level (not 1st, for magic-users); Duration 1hr/lvl.
Sleep: Affects d4 +1/lvl HD, Save WIS x 5 (large SIZ modifier applies, i.e. +1 per 10 over 10 SIZ [equals HD-1] ).
Magic Missile: 1 missile/lvl, d3/missile, Defence applies once.
Enlarge/Reduce: +/-20%/lvl.
Light/Cont.Light: Range Touch (Cont.: Duration 1 week; renewed by presence at religious service, if clerical). 
Silence: Does not prevent spell-casting.
Chaos: Save (20 - INT) x 5 and difficult.
    Also Illusionist spells have been incorporated into the normal list, some with (modified level) [and/or restricted to specialist illusionists]:
1st: Detect Illusion, Gaze Reflection, [Hypnotism], [Wall of Fog].  2nd: Change Self (I1), [Colour Spray (I1)], Fog Cloud.  3rd: Blindness (I2), Blur (I2), Continual Darkness, Deafness (I2), Dispel Illusion, Hypnotic Pattern (I2), Misdirection (I2), Non-detection.  4th: Illusionary Script (I3), Improved Invisibility, Improved Phantasmal Force (I2), Minor Creation, [Paralyzation (I3)], Shadow Monsters.  5th: [Chaos], Emotion (I4), Major Creation, [Phantasmal Killer (I4)], Spectral Force (I3), Summon Shadow.  6th: Conjure Animals, Demi-Shadow Monsters (I5), Dispel Exhaustion (I4), Mass Suggestion, Shadow Door (I5), Shadow Magic (I5), True Sight.  7th: Demi-Shadow Magic (I6), Permanent Illusion (I6), Programmed Illusion (I6), Shades (I6), Veil (I6), Vision.  8th: Prismatic Spray (I7), Prismatic Wall (I7).

Spell Additions  The following new spells are notable additions to the standard PHB lists:
Cantrips (M0): Standard (1s, VS); R 10ft; A: 5ft sq.; D: 1 turn; ST: Neg (?). Various minor effects. Learned singly, memorized as one.
Mage Armour (M1): Standard (1s, VSM); R: 0; A: Caster; D: 1 hour/level; ST: None. Protects like armour of 4AP value, at no penalty.
Wraithform (M3): Std (1s, SM); R: 0; A: Caster; D: 2min/lvl; ST: -. Become insubstantial, like a wraith (sunlight causes damage, etc)
Longevity (M9): CT: 1 Night (VSM); R: 0; A: Caster; D: Perm.; ST: Special (CONx5). Reduce age/delay death 2d6 yrs; caster save or die.
Protection  from Cantrips (M2): Std (2s, VS); R: 0; A: 1 individual; D: 1 hr/level; ST: -. Recipient not affected by any cantrips.
Prot. f. Skeletons/Zombies (M2): Std (2s, VSM); R: 0; A: 5ft.r; D: 1min/lvl; ST: -. Move with caster, broken if caster approaches.
Prot. f. Lesser Demons/Devils (M3): Std (3s, VSM); R: 0; A: 10ft r; D: 1min/lvl; ST: -. Physical/magical Type III/Lesser.
Prot. f. Were-type: (M4) Std (4s, V S); R: 0; A: 10ft r.; D: 1min/lvl; ST: -. Prevents entry by one type; moves with caster; approach breaks.
Prot. f. Undead (M4): Std (4s, VSM); R: 0; A: 5ft r.; D: 1min/lvl; ST: -. Prevents entry by any undead; moves with caster; approach breaks.
Prot. f. Elemental-type (M5): Std (5s, VSM); R: 0; A: 10ft r.; D: 1min/lvl; ST: -. Prevents entry by creatures of one element; moves, etc. 
Prot. f. Lycanthropes (M5): Std (5s, VSM); R: 0; A: 10ft r.; D: 1min/lvl; ST: -. Prevents entry by all were-creatures; moves, etc.
Prot. f. Petrification (M5): Std (5s, VSM); R: 0; A: 10ft r.; D: 1min/lvl; ST: -. All inside immune to any turning-to-stone effects; moves, etc.
Prot.  f. All Elementals (M6): Std (6s, VSM); R: 0; A: 10ft r.; D: 1min/lvl; ST: -. Prevents entry of all elemental creatures; moves, etc.
Prot. f. Greater Demons/Devils (M7): Std (7s, VSM); R: 0; A: 10ft r.; D: 1min/lvl; ST: -. Prevents entry/magic of relevant type; moves, etc.
Prot. f. Shape-Changers (M7):  Std (7s, VSM); R: 0; A: 10ft r.; D: 1min/lvl; ST: -. Prevents entry of al shape-shifting creatures; moves, etc.
Prot. f. Magic (M8): Std (8s, VSM); R: 0; A: 5ft r.; D: 1min/lvl; ST: -. Prevents entry/exit of magical effects; may de-magic items; moves.
Prot. f. Possession (M8): F.Rnd (VSM); R: 0; A: 10ft r.; D: Special; ST: -. Prevents any possession; lasts til caster moves, or 1 min/lvl.
Prot. f. Arch-Devils/Demon Lords (M9): CT: F.Rnd (VSM); R: 0; A: 10ft r.; D: 1min/lvl; ST: -. Prevents entry/magic of relevant type; etc.
Evil Eye (M1):  [ Necromancers only] Standard (1s, S) R: 10ft; A: 1 Person; D: 1 day/level;  ST: Neg. (WIS). Target suffers -1 on all saves.
Shadow Weapon (M2): [ Necromancers only] Std (2s, VSM); R: 0; A: 1wpn; D: 1rnd/lvl; ST: -. Att=STR +10%/lvl, -10%/2lbs wt, 3"/10%.
Speak With The Dead (M2): [ Necromancers only] As the 3rd level clerical spell.
Create Skeleton (M2): [ Necromancers only] CT: 1 Night (VSM); R: 0; A: 1 creature; D: Perm.; ST: -. Creates undead skeleton, 2PP/HD. 
Create Zombie (M3): [ Necromancers only] CT: 1 Night (VSM); R: 0; A: 1 creature; D: Perm.; ST: -. Creates undead zombie, 3PP/HD. 
Create Ghoul: (M4) [ Necromancers only]  CT: 1 Night (VSM); R: 0; A: 1 creature; D: Perm.; ST: -. Creates ghoul after 1 year, 4PP/HD. 
Cure Disease: (M4) [ Necromancers only] As the 3rd level clerical spell.
Control Undead (M7): [ Necromancers only] Std (4s, V S); R: 0; A: 30ft r.; D: 1turn; ST: Neg. (WISx5). Most undead must obey caster.
Viscid Globs (M2): [Restricted] Std (2s, VSM); R: 60ft; A: 2x2ft; D: 1rnd/lvl; ST: Neg (DEXx5). Bubble/rnd, irrevocably sticks target.
Wall of Tentacles (M7): [Restricted] CT: 1hr (VSM); R: 30ft; A: 20 x 20ft; D: Perm.; ST: -. Calls odd Daemon to serve as monstrous wall.
    Also Clerical spells:
Turn Undead: (C1) C: Standard (4s,VSM); R 0; A: 30ft in front; D: 1turn; ST: Neg (WISx5). Undead flee from presented holy symbol.
Sunburst: (C3) Std (3s, VSM); R: 60ft + 10ft/lvl; A: 20ft r.; D: 1s; ST: ½ (DEXx5). Blazing flash: d6/lvl v undead; all INTx5 or blind 1min.
    (Plus many other specialist miracles)