Adventure Fantasy Game does not have any specific supporting product. Chthonic Codex is meant to be the first one, and It’s becoming a multi-year opus, the first volume to be released later on this year.
But it doesn’t matter. The beauty of AFG is that you can just shamelessly yoink material from D&D and run it straight. What follows is what I do, in my head, without thinking about it much.
The important message is not to worry. Just roll with it. You literally can’t do anything wrong. AFG is a frame and just think of hanging stuff on it. Feel the freedom of running on the grass barefoot, nae, scratch that, with no clothes on. Be Bold. Take Risks. Enjoy the Rush. Make It Awesome.
Oh, beside that hippy moment, the best way to run AFG is without any worry and help players do awesome stuff. Treat it with the ingenuity of a pick up game and watch events unfold in a campaign. Seriously. RPGs like AFG are supposed to be a crutch/aid more than some kind of formal system that you can run your world in.
The Cruchy Grisly Bits
Spells: The handbook covers spell conversions. The only thing needed to convert is the spell level: double it and possibly subtract 1. All spells cost 1 mana. Keep all details unaltered. It works totally fine. If it feels weird to you, you’ll be comforted by remembering that casters can’t cast the same spell twice a day.
Modifiers/buffs: I wrote AFG to have a low number of modifiers and to keep them low in number. So anything that gives +1 to hit or skills is ignored. +2 to +4 becomes +1. +5 to +7 becomes +2 and so on. I often ignore everything that in D&D would give a +2 modifier. Avoid damage modifiers or add an extra dice of damage for weapons if you really feel you need to.
Monsters: HD becomes the AFG level. FC = tier. Recalculate damage ignoring the D&D damage. Give it equivalent armour. Keep the decor. That’s it, move along.
Riiight, you want more directions. Fine.
- FEARSOME FIGHTERS: If the monster is presented with many attacks or is supposedly awesome in melee, give it additional hits equal to its level or to double its level, as a fighter (and recalculate the FC).
- POWERS and SPELLS: If it comes with a list of powers, just use them or treat it as a caster of the same level with the listed powers as spell list.
- MULTIATTACK: If a monster is iconic for having multiple attacks, give it multiple attacks (say, hydras) or, if they hit, allow for multiple rolls of damage: for example if an aurumvorax (9HD, but might be different) wins a FIGHTMORE round, it will deal 1d6+2d6 (because FC 2) = 3d6 with the bite, plus 4 wounds of 1d6 each to be applied separately against armour for the hindlegs raking in.
- DAMAGE: recalculate the damage as if it was an AFG monster, considering that Giant (ogre-sized and more) monsters have the Giant ability, and that giant animals have it too (like the Ur-Bjorn in the example adventure). And remember that when you roll multiple dice for a wound, it’s always “take best, +1 for each extra 5MORE rolled on damage”, so the aurumvorax bite with a roll of (6,5,4) will deal 6,+1 for the 5.
- THACO and FC: If you have THAC0, try maybe FC = (20-thaco)/3, round down. Or maybe just ignore and get the FC from the tier. Or use FIGHTMORE with a d20 as suggested in the optional rules. Seriously, you should try this in a D&D game once in a while.
- ARMOUR: AC is converted to armour type (say, AC 2 becomes Plate), then converted to AFG armour (Heavy). Ignore Dex modifiers. So:
Saves: Ignore the save type or, if you use the separate saves suggested in the handbook, ask yourself the following questions:
- is it something that requires quick reactions and noticing things, like surprise? -> Roll on Alertness.
- Is it something that indimidates, scares or demotivates? -> Roll on Morale.
- Is it a physical attack, poison, petrification, tiredness, internal bleeding, mutilation? -> Roll on Toughness.
- Is it a mind probe, charm, compulsion, attack -> Roll on Stubborness.