Alternate spell prerequisite counts for Ritual Magic

[talus]

In my quest to adjust the prerequisite counts for Ritual Magic spells to make certain schools more accessible, I've generated several alternate counts using a script. In the process I found some errors in the published Thaumatology numbers. Details and spreadsheets follow...

The Ritual Magic system has spells as techniques which default off of a 'college' skill. The spell prerequisite count is the default penalty for each spell's technique. This allows mages to have extraordinary flexibility, but poses some problems with certain spells that have a very large number of prerequisites (especially in the Meta and Enchant schools). Some may, very reasonably, claim that this works as designed- ritual mages would be overpowered if they could easily cast every spell in the book- but I am not so sure. There are some very interesting linking spells are all but impossible for a ritual mage to cast.

Looking closely at the prerequisites for each spell I saw a common theme among the high prereq-count spells: non-specific spell requirements. These requirements are of the form 'x additional spells' or 'x spells from each of y colleges'. While specific spell requirements indicate to me a clear increase of complexity over the previous spell (easily justifying an increased penalty to cast), it seems that general spell requirements indicate only the need for general knowledge about spells- something a ritual mage has in spades. Therefore, I decided to experiment with reducing the cost of such 'general' spell requirements. (I also found some errors with the published counts- see 'Magic spell prerequisite count corrections' for details.)

Reducing the count for 'general' spell requirements by 50% make spells like Enchant much easier for ritual mages (the count goes from 10 to 5), as well as many other Enchantment and Meta spells. To try and understand the overall impact of these different methods I generated a graph comparing the 'difficulty' curve, or how many spells exist with each specific prereq count. It includes the RAW counts and a version using the optional 'advantage' counting rule: 1 per 10 full CPs.

Prerequisite count curve comparison: PrereqCurveCompare.png

Another interesting experiment was to check for specific advantage requirements separately- maybe a ritual mage without DX 11 should not be able to cast Iron Arm- which had the effect of increasing prereq counts for spells like Sense Danger (requires Sense Foes or the advantage of Danger Sense). I've collected all the various prerequisite counts for each spell in these spreadsheets. The xlsx version also has the graph.

Alternate spell prerequisite counts: AltRitualMagicPrereqCounts[csv/xlsx].zip
(RAW/Thaumatology, corrected, 1 per 10 CPs advantages, 'general' discount, specific advantage check experiment)

Finally, for those with experience running perl scripts, here is an archive of the script and all input data. You can use the script to generate various alternate counts including counts based on your mage's specific advantages. It includes RPK's balanced ritual magic GDF (from http://www.mygurps.com/r_magic.html), and has the capability to automatically updates the counts in the GDF. There is some very basic documentation in a Readme file.

Prerequisite counting script: MagicPrereqCalc.zip