Why is the approach in Urban Arcana so much more generous?
Put simply, the d20 Modern game is a different system. It allows characters to be more powerful in some ways than D&D does, but they are weaker in other ways. In fact, the Urban Arcana system doesn’t simply eliminate Hit Dice from the equation. If you look at the level adjustments for creatures with more than 1 Hit Die, you’ll see that they’re all higher than those for the corresponding creatures in D&D. They’re not high enough to make the creatures’ ECLs equal to those of their D&D counterparts, but they do help to close the gap a bit. However, there is one error in the Urban Arcana system. Replace the term Challenge Rating (or CR) with Effective Character Level (or ECL) everywhere that it appears on page 25 of the Urban Arcana Campaign Setting. Why does it matter? For one thing, since it’s a different quantity, it shouldn’t be called by the same name. For another, if you use the formula on page 25 to determine a creature’s CR, you may get a different result than you would using the s
