Develop the Concept

To begin, come up with the creature's concept. You likely already have the basic idea. As you add details to the general idea, taking notes can help keep your creature on track. Consider the parts of your creature you find most compelling and want to emphasize when the creature hits the table. For example, in Alien Core , typodaemons thrive on the subtle destruction wrought by their mischief and become sickened if you point out their intentional errors. Tax collector robots relentlessly pursue their targets but can be placated by paying a fine, as represented by their centerpiece ability, tax collector. Note your creature's core aspects, and if you feel uncertain later, you can look back and ask yourself, “Does this emphasize a core aspect or not?” Next, look at the creature's role in your game. Is it meant to be a combatant? A social creature? A trusted ally? Figuring this out will help you determine whether to give it strong combat abilities or to focus on skills, spells, and special abilities. Think about how the creature might behave if it's in a fight, if someone tries to talk to it, or if it's in a social situation. Does it work better alone or with allies? What sort of character should be best at facing it or be particularly weak against it? Also consider the complexity of the creature. This matters most when you plan to use a large number of creatures of that type. If you'll use five at the same time, you'll want their turns to move swiftly and avoid complex special actions. A creature that's likely to face a group of PCs alone can have more abilities, and it might need a more versatile set of defenses against PC tactics. Cut complexity as much as you can while retaining your desired theme. Now, how do you want an encounter with this creature to feel? Should it be scary? Mobile? Confusing? A mystical duel or a knockdown, drag-out fight? What can you give your creature to convey those characteristics? Much of this feel will come from your choice of the creature's special abilities or spells, rather than its raw numbers. With all this in mind, think about what specific abilities your creature should have. Take a few notes now, and get to the details later. You can use abilities from Alien Core or feats in Player Core , adjusting as needed, to save yourself time. It helps to think of a creature that's similar to yours and see what makes it tick—and what you can steal from it. Maybe you can just reskin that creature (sidebar Reskinning a Creature), instead of making a new one from scratch. Now that you understand your creature's concept, it's time to get to the statistics. Remember that you can always change your concept later on. Your creation might evolve and transform as you go, so be open to change. Converting First Edition Creatures If you're converting creatures from First Edition, you won't find a direct numerical conversion. Instead, use the original statistics to create your road map, giving a better AC to a creature that had a good AC in First Edition, and so on. Here are the main areas of difference that you'll want to keep in mind for your conversion. Attribute modifiers scale differently, so don't copy them exactly. The highest modifiers tend not to get as high in Second Edition. You'll rarely see a +10 Strength modifier, for example. Creatures also tend to get better low statistics at higher levels than they used to, particularly for Dexterity and Wisdom. This is most apparent in high-level First Edition creatures with awful Dexterity. Low-Intelligence creatures, particularly animals, tend to have more special actions than they would have in First Edition. This is to make encounters with them more dynamic and distinct. Compare dinosaurs between the editions for good examples. When converting spell-like abilities to innate spells, you might need to make some substitutions. Some spells will appear as heightened versions of spells (such as greater dispel magic now being heightened dispel magic ), but others will require you to find something different. Also, don't feel like you need to keep every spell; focus on the most thematic and potent ones. The Spells section has more advice on this subject. Damage reduction has been replaced with two options: resistance to all damage (possibly with exceptions), or more HP and a weakness. Immunities, Weaknesses, and Resistances describes the distinction. If you want to convert spell resistance, you can give the creature a +1 status bonus to all saves against magic, or +2 if it had abnormally high spell resistance for its level. Improvising a Creature As you get more experienced, you might find that you don't need to build some creatures in advance. In many cases, especially for simple creatures, you can just select values from the relevant tables on the fly and track its HP. When you do, track which value you used as it came up. For instance, let's say you're improvising a 2nd-level free captain gunner. When it's time for initiative, you decide it has moderate Perception and jot down “Per +8.” Your group's fighter beats it at initiative and attacks. You decide the gunner has high AC—looking at the Armor Class table, you see that's 18—and add this information to your note. The fighter's Strike hits, and you select the low end of high HP: 36. Well, now it's 25. Your note says, “Per +8, AC 18, HP 25.” If it gets to take a turn, you can give it a Strike then.