Here are my thoughts (as of this moment) about how to run spontaneous magic for ArM5 newbies. I doubt any of this is new to these forums, but I'll try to put it together in a helpful way.
First, yes, on their character sheet list the 5x10 table with their Te+Fo+Sta already calculated for them. Also give them access to the R/D/T magnitude table as in Arthur's post (although I'd just leave off Year and Boundary).
Then, introduce the following system for casting spells. Everything is centered around the basic sponted spell being a Base 5 Personal/Momentary/Individual spell. Every spell costs a certain number of "casting tokens" (couldn't resist!) - poker chips or similar - to cast.
How much does a spell cost? Instead of listing the spell guidelines as Base 1, 2, 3, 4, 5, 10, etc., list them as follows:
- list Base 1 guidelines as "costs 1 token; get 4 free mini-tokens"
- list Base 2 guidelines as "costs 1 token; get 3 free mini-tokens"
- list Base 3 guidelines as "costs 1 token; get 2 free mini-tokens"
- list Base 4 guidelines as "costs 1 token; get 1 free mini-token"
- list Base 5 guidelines as "costs 1 token"
- list Base 10 guidelines as "costs 2 tokens"
- list Base 15 guidelines as "costs 3 tokens", etc.
Then give then the R/D/T table as above, but say "costs X tokens" instead of "+X magnitudes". Mini-tokens can be used to offset the cost of these R/D/T tokens.
How many tokens do you get to cast the spell? You take your listed Te+Fo+Sta total and add a die roll (simple or stress). In addition, if you have mini-tokens left over, each one gives you +2 on this total. You get the total/10 tokens (rounded down) to cast the spell (equivalently, if your total is a two-digit number, then the first digit is the number of tokens you get).
For example: turn a rock into a faint nightlight that lasts all night.
How much does it cost? "Create light equivalent to moonlight" is listed as "costs 1 token; get 4 free mini-tokens". You need to touch the rock, so spend one mini-token; you want it to last all night, so spend two more mini-tokens. You have one mini-token left over, so you'll compute Cr+Ig+Sta +2 (mini-token) + die roll. It costs 1 token, so the total needs to be 10 or higher.
For example: a lite version of Arc of Fiery Ribbons, that does only +5 damage.
How much does it cost? "Create fire that causes +5 damage" is listed as "costs 1 token; get 1 free mini-token". Voice range costs 2 tokens, one of which can be paid using the mini-token. Group costs 2 tokens. Total cost is 4 tokens. You'll compute Cr+Ig+Sta + die roll, needing 40 or higher.
For example: Perception of the Conflicting Motives.
How much does it cost? "Sense all of the emotions in a being" is listed as "costs 2 tokens". Eye range adds 1 token; total cost is 3 tokens. You'll compute In+Me+Sta + die roll, needing 30 or higher.
Players will quickly see that they have a decent chance at 1-token spells in general and 2-token spells in their specialties, possibly higher depending on their magi's power level.
(This all ignores Penetration - they shouldn't be sponting spells at baddies anyway! - but the SG can do the calculation for them if necessary.)