Rules Clarifications: Spells

Memorizing/Praying for Spells (see pages 154-156 of PHB)

Wizards require 8 hours of rest in order to memorize their spells, even if they are elves (you otherwise only need 4 hours of ‘trance’ or ‘reverie’ in order to physically recover.  They then spend between 15 minutes (minimum – for a portion of their spells) to an hour (for ALL of their spells) studying their spellbook – in effect they are casting the spell up to a point shortly before completion such that, when under pressure, they only have to complete the final aspects of the ritual to unlock the spell.

Clerics and Druids are similar but do not study their spellbooks and instead spend a particular time of each day (usually morning or noon for good or neutral deities) in prayer.  Divine spellcasters do not have the stringent requirement of a period of rest to memorize their spells, so an elven Druid or Cleric only need ‘trance’ or ‘reverie’ for 4 hours so long as they pray at the proper time.

Casting Time: (found in each spell description)

Spells with a casting time of 1 action count as a standard action, just like an attack, which means you still have a move action remaining.  Eg. Lareth can cast magic missile and still move.

Spells with a casting time of 1 round (6 seconds) obviously don’t allow you a move action.

Other durations are worked out accordingly: eg. a spell which has a casting time of 1 minute takes 10 rounds to cast (remember, 1 round is six seconds).

See also 'Casting Time' on page 148 of PHB.

Range: (found in each spell description).

The maximum distance a spell’s effect can occur.

• Personal (only effects self)
• Touch
• Close (25 ft and 5 ft for every 2 levels)
• Medium (100 ft and 10 ft per level)
• Long (400 ft and 40 ft per level 

See also 'Range' on page 148.

Spell Components:

Each spell has a combination Verbal (V – magic incantations - abracadabra?), Somatic (S – this means gestures) and Material (M – eye of newt kind of thing) which are required in order to cast the spell. 

If you are silenced you cannot use (V) spells, if you do not have a hand free you cannot use (S) spells and if you cannot access your material components you cannot use (M) spells.  You are assumed to have the required material components for a spell in your component pouch UNLESS a price is listed in the spell description, in which  case you have to buy the component before you can cast the spell.

More is at 'Components' on page 151 of the PHB.