I understand that the Laundry RPG (based on Stross' books) utilizes a modified version of the BRP (Call of Cthulhu). What changes/differences with the BRP? Additions?
I'm pretty much only familiar with BRP through Call of Cthulhu, and I don't actually own a copy of The Laundry yet, but I'll give a quick run-down of what I've been able to dig up.
Charisma stat replaces Appearance
No Magic Points
Personality Type is selected during character creation, adding an additional 20 skill points which are distributed between specific personality-appropriate skills. Personality choices include:
- Master (as in craftsman)
- Nutter (also starts with an insanity)
Laundry Assignment/Training is selected during character creation. Grants +10 bonus to several skills. (This is in addition to Call of Cthulhu-style professions.) Choices include:
- Computational Demonology
- Contracts and Bindings
- Information Technology
- Media Relations
- Medical and Psychological
- Occult Forensics
- Plumber (that being what the Laundry call their paramilitary clean-up operatives)
Wealth Levels instead of specific savings and income.
Some changes to skill list
The big mechanical change is apparently a new magic system. It covers traditional/ritual magic, Laundry-style computational magic, and "mental" magic (which is casting spells without external aid). As noted above, Magic Points are out, but casting now requires a skill check with a Sorcery skill.
Combat and investigation are streamlined, although I haven't seen anything about exactly how. Also, nice things were said about the sanity system.
Special Successes (rolling under 1/5 of your skill) replace criticals/impales. On attack rolls, they do double damage. Outside of combat, I think they're just extra good successes without any special rules.