The TDE spell system is very dissimilar to that of GURPS Magic in that spells have no prerequisits, fancy names and knowlege of spells heaviely depends on who you are. On the other hand it is very similar in that it organizes in colleges, and has one skill per spell.
An other issue is the feeling: Is it realy the same whether the archmage throws an "Ignifaxus" or a "Flame Jet"?
Ritual Magic
To emulate different magical traditions and to ignore prerequisits one of the best solutions is probably to use the "Ritual Magic" system as discribed in the Basic Set (p. 242) and in more detail in GURPS Magic (p. 200).
Each magical tradition (magecraft, witchcraft, druid lore, elven lore etc.) uses its own speciality of Ritual Magic. Colleges are IQ/VH Skills with Magic Ritual as their prerequisit and spells as their techniques.
Rituals (mage's staff enchantments, elf's magic songs etc.) are probably best modeled as magical powers with Magery as talent.
Changes to the Default System
To reflect aventurias six elements one could introduce two additional colleges: Ice and Rock/Metal. And to better reflect the properties of Humus use the Plant instead of the Earth college (In fact there are very few spells that have TDE correspondence in the Earth College)
Elves use the Musical Influence Skill instead of Magical Ritual to better reflect their affinity to Music.
Mages use Thaumatology instead of Magical Ritual
Witches use Herb Lore instead of Magical Ritual
Flare
To get more of the TDE flare one could rename GURPS spells:
The material presented here is the original creation of the contributors, intended for use with the GURPS system from Steve Jackson Games. This material is not official and is not endorsed by Steve Jackson Games.
