I don't really have the time or inclination to be writing lots of new adventures for my group, so I prefer to run published modules, often D&D or Pathfinder ones (which I usually customise to some degree) and convert them over to BBF.
Most conversions are relatively straightforward, for monsters I try to find a BBF equivalent, sometimes making them more or less powerful. Traps are easy to convert. Magic items are easy to convert too, but as I don't have as many magic items in my games as typical D&D/PF I either leave them out or tweak their abilities. When it came to converting Difficulty Checks to skill modifiers I found this page useful: http://hackslashmaster.blogspot.co.uk/2014/11/on-updated-rosetta-stone.html
Then there are the NPC's. I only go for very rough approximations of the equivalent D&D/PF stats and skills, trying to build them as a BBF character would be built. Where it becomes tricky though is when there is an NPC with spells. In D&D/PF NPC wizards tend to have a greater number of more specific spells, plus they have the restrictions of a Vancian magic system (yay BBF!). With BBF there are fewer spells with each having a wider range of uses.
If anyone else has done this, how have you mapped D&D/PF spells to BBF?
One example I have is a level 1 Gnome Bard NPC from the One on One Adventures Compendium, with the following spells:
Spell-like Abilities (CL1)
1/day—dancing lights, ghost sound (DC 14), prestidigitation,
speak with animals
Spells Known (CL1)
1st (2/day)—cure light wounds, sleep (DC 14)
0—daze (DC 13), detect magic, lullaby (DC 13), mage hand
When I converted this character the closest I could get them too is Scholar 1 (Primary), Spellcaster 1, Thief 0 (Secondary) which gives them one BBF spell - in this case I chose Illusion because it covered dancing lights and ghost sounds, plus Wizards Eye equates to detect magic and Low Wizardry to prestidigitation. Unless I make the NPC a much higher rank, they won't have many other spells - such as Heal and Charm.
I'm looking for any ideas on this part of converting NPC's...