I am running an LotFP adventure for my group; we play using the Final Playtest ruleset of D&D Next.
LotFP is part of the old school renaissance, and James Raggi (the creator) writes that it should be generally usable for many D&D-like systems. I tried converting some of my own, but I would gladly take some advice on how to do it right. In the first session, I generally looked up similar monsters in the bestiary or wotc preview adventures, but a generic formula that gets most right would be best.
So… what's the best way to convert the monsters from LotFP to D&D Next? Not sure about the AC, but it seems to me the HP should be increased. And how to handle attack boni? I did make a table to convert the oldschool saves to the best-fitting vs. ability saves, e.g. save vs. Poison -> Constitution and save vs Magic -> Intelligence. But I'm not sure about the numbers…
The party is currently Level 2, but a formula that takes level into account would be preferable.
Some example creatures:
Armor 17, 2 Hit Dice (but with Hit Points of an 8 Hit Dice creature), Movement 120’, 1 bite attack doing 1d6 damage, Morale 9. Armor 15, 2 Hit Dice, Movement 90’, 1 bite attack doing 1d4 damage and 1 pincer attack doing 1d6 damage (continuous after the first round), Morale 5. Armor 18, 8 Hit Dice (but strike only as 2 Hit Dice creatures), Movement 120’, one bite attack for d6 damage, Morale 8. Anyone taking damage much save versus Poison or be infected with a random type of disease which will take hold in 1d10 days.