Incantation, dynamic spellcasting

Advanced d20 Magic » Incantation, dynamic spellcasting
Many spells may be used with an Incantation ? a ritual chant to help focus magical energies. By using an Incantation
associated with a spell, the character can make the process of casting the spell easier. When using an Incantation, the character must take a full round to cast the spell. That is, the character must spend all his or her actions during the round to cast the spell, and the spell is still not complete until the character?s Initiative on the following round. This gives everyone around ample opportunity to attempt to interrupt the spell.
In addition, anyone who can hear the Incantation and recognises it will immediately know what spell the character is casting. If the GM is uncertain whether a particular character would recognise the Incantation, a Knowledge (Arcane) (or Spellcraft) check may be made. The DC of this check depends on how likely the character is to have knowledge of that spell, and may range from DC 15 up to DC 30 or more for truly obscure magic. In most cases, using half of the spell?s DC for this check is appropriate.
The advantage of using an Incantation is that the character gains a +5 bonus to the Fortitude Save to resist Spell Drain and to the Control check (if one is required). This bonus stacks with the bonus for Invocation (the two are often used together). Further, the DCs of saving throws against the spell are increased by +2 if Incantation is used.