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Guidelines

Source Alien Archive 2 pg. 138
You can add some or all of the abilities and skills listed in an environmental graft to adapt a creature into one appropriate for that environment. If you wish, you can also remove abilities not needed in the environment—if you decide to turn a burrowing creature into an aquatic creature, it likely no longer needs burrowing (although if you want a sea monster that can also dig through sandy beaches, you might keep the burrowing ability). The following guidelines also offer guidance on how to adjust natural attacks, skills, special abilities, speed and movement types, and senses when adjusting a creature to a new environment. You can also use these guidelines to make ad hoc adjustments to creatures when adapting them without using a template graft of any kind.

Natural Attacks

You can always change a creature’s natural attacks to match a different body shape. If you want to use the stat block for a creature that has a tail smash for a creature that instead has sharp claws, that’s as easy as switching the name of the attack and changing the damage type from bludgeoning to slashing.

Senses

Creatures have keen senses, which can be expressed by raising good Perception to master level when a particular sense is involved. Other senses sharper than the human norm are usually free abilities. They have low-light vision by default, but that inclusion is optional. Many species, especially those that operate in environments where sight can be unreliable, have blindsense related to scent, sound, or vibration. Creatures that commonly hunt warm-blooded prey, such as snakes, have blindsense sensitive to heat. A blindsense range of 30 feet or less is most common. A creature with particularly keen nightvision might qualify for darkvision with a range of 60 feet, although such vision is often coupled with light blindness.

Some species enjoy even keener special senses. A predator that has blindsense (scent) might also have tracking (scent), for instance. Other creatures, such as dolphins, have blindsight (sound) due to sonar or similar capabilities. The range on such an ability can be quite large, up to 120 feet. Such sharpness in one sense can be coupled with weakness in another. Some creatures that have blindsense or blindsight have poor vision and could have the sightless trait.

Skills

The skills listed in each environmental graft are gained as good skills if the creature does not already have them. If the creature has the listed skill as a good skill already, it becomes a master skill. Some skill are listed with (master) after them; these are always gained as master skills. If there are any common adjustments to these skills, they are listed afterward. These additions do not count against the creature’s normal number of good and master skills (though again, you may wish to remove any skills that do not match your new creature concept). You can always adjust a creature’s good and master skills to match a different body shape.

Special Abilities

In addition to any changes listed in an environmental graft, you can add or exchange extraordinary abilities to a creature to match a new body type or make it interact differently in combat. You can also look at the special abilities granted to existing creatures and use them to create new creatures that fill similar roles. For example, the dinosaur entry (see page 38) has entries for pterosaur (with the Spring Attack feat), dromaeosaurid (with pounce), ceratopsid and sauropod (both with trample), and theropod (with swallow whole). One way to change these stat blocks to represent new creatures is to change out these special abilities. If you were making a new creature based on the sauropod stat block but you wanted it to have huge tentacles, you could select the grab ability from the universal creature rules and replace the sauropod’s tail attack and trample ability with a tentacle attack (with the same attack bonus and damage) with grab. Alternatively you could decide it has enormous spikes on its tail, and that it can swing its tail over its head like a lance when charging, and give it the dromaeosaurid’s pounce ability instead of trample.

Speed And Movement Types

Changing what environment a creature operates in often calls for a change in its movement modes and speed. You can increase a creature’s speed up to double or decrease it by up to half, based on your concept. Other creatures are faster in a given context, such as when taking the charge, run, or withdraw action. Many creatures also have different movement types, depending on their native environments, and some gain movement types from environmental grafts. The following generalities can help you customize an individual creature’s speeds, or when using environmental grafts. While these guidelines reference a creature’s land speed for comparison’s sake, for creatures without land speeds you can use whatever movement type they have.

Burrowing: Numerous creatures slowly excavate tunnels, dens, or warrens, but only a few dig quickly enough to do so in combat. A burrowing creature typically has a burrow speed one-half to two-thirds as fast as its land speed.

Climbing: A creature that has a climb speed typically has a climb speed from one-half as fast as its land speed to the same as its land speed. If a creature can climb across ceilings, it has the spider climb universal creature rule.

Flying: If a creature uses biological methods to fly (most often wings, but some creatures have other means, such as skin flaps, gas sacs, or sails), this ability is extraordinary. Fly speeds vary greatly, from half or less of a creature’s land speed up to two or three times as fast as its land speed. When you give a creature a fly speed, give it a maneuverability rating of clumsy, average, or perfect based on how nimble you wish it to be.

Some airborne creatures are clumsy when grounded. A creature like this has a land speed lower than those in the generic stat blocks. A creature that can jump well can either be given a fly speed that requires it to land at the end of every move, or just have Athletics as a master skill.

Swimming: A creature that’s a good swimmer has a swim speed as fast as the land speed in its generic stat block. A great swimmer might have a swim speed two or three times this number—especially if its land speed is less than 30 feet. A great swimmer’s effective land speed might even be as low as 0 feet.