I've run two sessions of Cuccagna on G+, and it looks like that's going to be a going concern. As such, here are some guidelines for FLAILSNAILS characters who wish to adventure in that enchanted isle.
- Ability Scores: All characters keep their original ability scores, but use the modifiers listed in the Cuccagna Character generation document instead of those of their native system.
- Character Classes: Non-native characters are treated as the class that their character most resembles in Cuccagna (Fighters and Paladins are Warriors, Magic-Users and Sorcerers are Wizards, Thieves and Assassins are Mountebanks, etc.).
- Clerics: the Gods of Man have no apparent place on Cuccagna. Clerics who arrive in Cuccagna find that their spells no longer work. As such, they are treated as Warriors of equivalent level.
- Demi-Humans: Demi-humans are treated as their Swords & Wizardry White Box equivalent, though they will be looked on with great suspicion by the locals. Demi-humans that do not have S&W equivalents are treated as the closest class.
- Hit Dice: FLAILSNAILS characters reroll their HD at the beginning of each session.
- Level Cap: There is currently a soft level cap of 3. This will be raised as more adventuring sites are added.
- Mundane and Magical Equipment: This game is considered Diet FLAILSNAILS; however, magical items always function as determined by the DM (i.e. me). If there is too little time to run an item passed me, then it will function under the FLAILSNAILS Blue rules.
- Spells: Spells for non-native characters function either as they do in the Swords & Wizardry White Box or in the Swords & Wizardry Core Rules. Spells from Cuccagna function as per the Dying Earth Spells for D&D pdf.
- Languages: Non-native characters know whatever languages they already knew. New languages are gained as per the LotFP language rules.
The character creation document can be found here. Equipment for new characters is purchased either from the Swords & Wizardry White Box, or from B/X.
EDIT: changed the link to the character creation document to a new, updated version.