Building Creatures

Making your own creatures fleshes out your game world and lets you introduce concepts not yet available in published products like Alien Core and similar volumes. These guidelines help you customize creatures to your specifications and explore your imagination. From alien monsters to corporate masterminds, you have the power to design creatures that fit the narrative needs of your story. Creatures aren't built the same way PCs are. The rules for building them are more flexible, and their statistics are based on benchmark final numbers rather than combining each individual modifier together. This is called top-down design, in which you consider the design process as a whole and select the details that reflect your intended result, rather than building statistics from the bottom up and hoping the finished creature matches your vision. This guide provides a step-by-step process to build creatures, but as you get more comfortable with creature creation, you might prefer to use different methods. You could start with one ability you think is cool, or you might look to create a spellcaster of a certain type. There's no wrong starting place or wrong way to compile and present your creation; some GMs prefer to generate a stat block that's as similar to an official Alien Core entry as possible, while others prefer just a brief set of notes. Building Creatures Overview This section details the creature-building process using the following steps. Develop the Concept Think about your creature, and make notes you can use in future steps. Build the Stat Block Pick all the statistics for the creatures, going through the list below. Level Size and Traits Attribute Modifiers Perception and Senses Languages Skills Items, if necessary AC Saving Throws Hit Points Immunities, Weaknesses, and Resistances Speed Strikes, including their damage Spells, if necessary Design Abilities Create the special abilities your creature can use. Review Holistically Step back, take stock of your creature as a whole, and tweak as needed. Building NPCs Sometimes you'll design a creature that's meant to have abilities or characteristics similar to those of a PC. Maybe you need a fashionable envoy, a cunning operative assassin, or a wise mystic for your game. You also might need a common construction worker, who has little combat ability but great skill with tools and heavy machinery. This section provides ways you might modify aspects of the creature-building process to fit those needs. Reskinning a Creature Sometimes you need a creature with abilities that are almost exactly the same as those of a published creature. In that case, it can be more efficient to simply “reskin” the old creature rather than design a new one—that is, to change the description but keep the abilities mostly the same. Occasionally, reskinning requires small mechanical adjustments. For instance, an ice squox that has immunity to cold, an aura that deals cold damage, and the ability to freeze people in place with its jaws to deal persistent cold damage and suppress them could be reskinned as a caustic animate tree that has immunity to acid, an aura that deals acid damage, and branch attacks that smear sticky acidic sap on a creature's body when it hits, dealing persistent acid damage and suppressing them. Trait Abilities This section provides the abilities conveyed by certain traits, such as dragon, robot, and undead. You'll also find abilities typical of creatures with those traits to help guide you as you plan your creatures.