Like the lich Acererak, who uses the souls of mortals to enhance his dark magic, you can use published adventures from other systems to enhance your campaign!

Fortunately, Whirlwind is a relatively simple game compared to others, and so converting adventures made for other systems for use with the Whirlwind rules is relatively easy. This section will assume you are converting an adventure made for 5th edition dungeons and dragons, but the advice should be broadly applicable to similar games such as Pathfinder and 13th age as well.

Combat

5th edition adventures will tend to include a fair amount of combat - it can be worthwhile, given Whirlwind’s different emphasis, to try actively to offer players more ways of moving past such encounter without fighting. When modules say that monsters will attack players on sight (or use other language indicating that a fight is all but inevitable), consider changing this to give the players more freedom in determining how they will approach the situation.

If the players do choose to fight, this should be handled as a skill challenge. For particularly involved or large fights, perhaps multiple skill challenges, with each one representing a different ‘phase’ of the fight (one to deal with the boss’ minions, one to deal with the boss’ magical or trap defences, one to deal with the boss itself).

Saving Throws, and Skill Checks

When a 5th edition adventure says that a character would be subject to an effect unless they make a saving throw, let them make a skill check to try and resist the effect.

There is no easy formula to convert DCs in 5th edition to DCs in Whirlwind, but eyeballing DCs is easy enough based on the description of what the character is up against.

Gold & Magic Items

Gold and valuable objects players find in 5th edition adventures can be given at its same gold value in Whirlwind, and likewise with other games such as 13th age and Pathfinder.

Magic items should be removed, with consumable items removed with the replacement of some treasure with a gold piece value (replace scrolls with rate books, replace potions with rare alchemical ingredients, etc). Permeant magic items should be replaced with luxury artifacts, unless the ability granted by the magic item is relied upon within the 5e adventure in a meaningful way - then it should be converted to a story artifact (ordinarily, a key item).