The illusionist being one of the easiest ways to do it. The Phantasm X spell (level 20) should be sufficient. It will give x512 damage, so you only need to score an 88 on the MA table to do 1024 damage.
Rulings about the damage can be found in the Main Rulebook on PG 206-207.
I found it, in my RMFRP book are in the Spell Law book at page 98.
Well, I now understand why this sounds rare to me, we begin to play with RM2 which no had this rule of damage, and habit is strong so we forgot it.
But, dragons apart, I should say that this rule sounds bad for me, with this you can easily kill a strong fighter or any other normal creature with only 1 hit!, who needs criticals if you can deplete 150-200HP per hit easily?. Another "point" is that illusionist only needs to develop 1
directed spell skill, the phantasm one, so it can be maximized easily with 2 ranks/lvl and bonus to that specific skill.
How can exists a rule that multiplies damage by itself instead use the sum?, I am sure there is the only one of this type on all RM books, and IMO it is unbalanced.
I really don't understand how a profession of type "trick" can be converted to one of the more powerfull in combat only with 1 spell and 1 skill (phantasm and its DS). You need high level, but other professions (spell users included) has no cheats like this one even at high level.
IMO a better solution would had been split that damage between multiple attacks, this is, use the sum as multiplier for damage but allows to do more attacks, and if you think about it it is more realistic, you can create a troll phantasm, and attack with good damage (x5, x6, x8...) but in multiple rounds simulating a real combat, not only in 1 hit and then the phantasm feel is out.
Those damages x64, x256, x512
![Shocked :o](https://ironcrown.co.uk/ICEforums/Smileys/default/shocked.gif)
...sound very rare to me (we are using RM and not AD&D right?) and I think those illusion effects should be revised to create more realistic situations.