Is there something… different about the binding used in the 5th ed books? My cat really enjoys them. I mean, she’ll sit on them, chew on them… ignores other books, even other hardcover books. It seems like she’s equally into the supplements as to the main rules.
I am also open to the option of having strange cats.
Tome of Feline Craving, ReAn 43
Any cat seeing this text finds it irresistable. She will sit on it, chew on it, etc. to the exclusion of all other activities and pursuits.
(Base 5, +2 Sun, +3 Sight, +3 levels environmental trigger, +10 levels unlimited uses)
This enchantment was originally created as a trap for a certain Thomas of Bjornaer by one Simon of Bonisagus, who had far too much time on his hands. As Simon's friends repeatedly told him, hiding catnip between the leaves of the book would have worked just as well.
(Please forgive me for this one. I couldn't resist. I'm also not sure if the use of environmental trigger is appropriate in this case, but I've never been able to figure out that item modifier.)
If you put +2 Sun and +3 environmental trigger, you only need 2 uses per day (1 at sunrise, 1 at sunset) to have the invested power work constantly. 
This way it can target an infinite number of cats - every cat that sees it (environmental trigger) gets zapped with the duration sun spell. Come sunset/sunrise the cats are free.... until they look at the book again.
This isn't a constant effect.
I'd be of the opinion that a cat looking at the book isn't a magically significant occurance so I might require an InAn spell with a linked trigger.
I think that the smart way to do it would be range touch target room with the constant duration modification.
base 5, +1 range touch, + 2 duration sun, +2 target room, +3 levels environmental trigger, +1 level 2 uses per day => level 34
Ah, I see, you're right. 
You are all crazy and one of my two cats LOVES Ars 5.
Has one of you been casting spells at me?
I think you should include your familiar in your game...The creature is probably jealeous of the time you spend with the other four...
8)
Actually, she played the familiar of one of the characters in a fourth ed. game.
She'd even roll the dice. Of course, she'd roll them right off the table and under the heating ducts...
See, that's the thing I've never quite understood about environmental triggers. The two published instances I can think of trigger off the existence of fire in a room (see the "Fire Guardian" in the Semita Errabunda write-up) and opening a door ("The Crystal of a Hundred Candles" from Guardians of the Forest). Neither one of those seems like a “magically significant occurrence†to me, so I'm rather unsure of what counts. Looking at an object seemed about as significant to me as opening a door.
(Of course, both published instances could be incorrect applications of the rules; it isn't reasonable to expect published material to be wholly free from error. However, these are the only two published examples of which I am aware, so they are only examples I have to go on.)
Checking the archives, I find that you and I have been over this territory before.
Hmm... I’ve never quite been sure how to create constant effect devices (like this) whose target can dynamically be altered. In particular, is there a set time that a constant effect device activates? The obvious first reaction is, “No, of course not. Go read the text on page 99.†However, does the fact that the device is constant insofar as it doesn’t “flicker†change the fact that it’s still a Sun duration enchantment that activates twice a day? What would happen, for instance, if a magus removed cats from or introduced cats to the room? Similarly, what would happen if the magus removed the book from one room and carried it to another? Would all the cats in the first room cease being enchanted and all the cats in the second room suddenly become enchanted?
The most interesting and convenient answer is probably, “Yes.†If you take the approach that “constant†is really shorthand for “doesn’t ‘flicker’ when the device reactivates itself at sunrise and sunset,†then the cats in the first room would continue to be interested in the book and the cats in the second room would continue to be disinterested until the next sunrise/sunset. Likewise, cats would only be enchanted if they were in the room with the book at sunrise or sunset when the device activates.
In actual play, I’d probably choose “yes†out of convenience. The above is more of a thought experiment on a system feature whose ramifications I don’t fully understand.
Problem here - this means that any cat not present during sunrise or sunset will be unaffected. By having unlimited uses, you could have the effect trigger every time the sun moves - thus having an effect that TRIGGERS constantly.
You're quite right, this is something that isn't clear.
Thinking about it, (it hasn't come up for me in play yet) I tend to consider what would be an appropriate triggering action if the item were not environmentally triggered (like a particualr way of waving a wand, a command word, placing a ring on one's finger) and use this as a sort of benchmark for what needs to be an environmental trigger.
Walking through an enchanted doorway, touching an enchanted object, and speaking a particular word while touching the object are all examples of things that I think might be examples of triggering actions and do not need an environmental trigger.
Obvious things that could probably done with environmental triggers are a particular date, when a certain number of people are within a room, when a threat is made within range of an object, when a sword is drawn in the same room as the device, the two examples from published material.
Stuff that needs a linked trigger would be inperceivable or possibly inperceivable things; thoughts, a hidden knife, or a document dealing with a particualr topic
looking this over again I'm tempted to allow the environmental trigger for being looked at by a cat after all. Perhaps I responded too quickly.
(Now I'll go back and see what my opinions were a few months ago.)
I hadn't considered the issue of dynamically altering targets.
I'm not sure that I don't like the option of having the cats in the first room instantly loose their enchantment when the book has left the room. Do you see any specific situations where either of these two solutions (dynamicaly altering or refreshing at sunrise/ sunset) cause problems?
Prior to your comments in the above-mentioned thread, I interpreted “major magical features of the environment†far more restrictively than you did. I didn’t think that one should analogize from normal activation behaviors, and I came away from the core book with the impression that changes in aura or events that ended spell durations were pretty much it. That having been said, I like your interpretation a lot better than my original one. On that way of thinking, there is very little one can do with an environmental trigger.
In the end, it seems that an environmental trigger should be allowed to activate due to:
Is this a reasonable summary of your position? I hope so, since I think I’m trying to agree with it.
While the division is somewhat subjective, I do think these two points are different. Unless the Grimoire of Uncleane Incantationes is burning, I don’t really see how a fire in the library is magically significant. (OK, a library fire could ruin your plans to read up on Intellego, but it isn’t itself magical.)
Now, if you’re inclined to a philosophical bent, you can still tie yourself in knots trying to disambiguate “obvious to most observers†and “little to no interpretation,†but my inclination would be to leave it to the SG at that point. I’d even recommend that the hypothetical SG show people your list, all of which (with one possible exception) are things I would agree ought to be covered by an environmental trigger.
(The possible exception is making a threat within range of the object. Except under tightly defined conditions, the concept of “threat†requires a little too much interpretation for my taste, though YMMV. Tightly defined conditions would probably include a stated intention to cause bodily harm in a language the inventor understood. It probably wouldn’t include dark glares, saying “or else,†or vague hints at consequences. I would also think that the trigger shouldn’t be smart enough to distinguish between actual intention and hyperbole, so watch the trash-talk before certamen.)
Well, if you’re looking for problems, someone might consider the “dynamically altering target†option to be a little too powerful. I don’t see either option as problematic, per se, but I do think they would have different in-game effects. In particular, I’m not sure that enchanting only the cats in the current room at sunrise and sunset would be the type of behavior I wanted. Enchanting each individual cat was my way of having my kitty-zahir cast as wide a net as possible, and one could get the same effect more efficiently under the “dynamically altering target†option. If the enchantment merely refreshed at sunrise/sunset, it wouldn’t quite do what I was after.
it means the device is "Always On". It is a copy of the canonical description in 5e for "how you make a device effect which is always active".
I do not believe the continuous movement of the sun has anything to do with the triggering of a spell-to-affect-cats. (Other than Always On, a Cat Target is required for the effect to be triggered...)
Now the question becomes - can such an effect act of an arbitrary number of cats?
If it were an always-on-thorny stick (yes - the thorns do the work)
Always on burning stick (yes the flames do the work)
Always on catnip scent (yes - the scent works indirectly)
The core book includes an Invisibility Ring as an example "always on" effect, with the twist that it makes invisible whoever puts it on their finger, while it's on. Some might say that is stretching the definition of Always On, others think that's exactly what it is.
The Cat effect stretches it one stage further - we have a single effect designed to Target an Individual Cat, but we actually desire to affect any cat approaching.
I would suggest that an Always On, Individual Effect can affect any single cat that approaches and remains within the the designated area, but cannot affect more than one cat at a time. (Always On, Group could I suppose affect any group of cats within the area?)
For myself, I find this is definitiely stretching the Always On design beyond the limits, and would prefer an N-uses-per-day effect triggered by approach.
[The key difference between Always On and Unlimited Uses is supposed to be that Always On is uncontrolled, lacking selectivity, whereas Unlimited Uses can be restricted to chosen targets.]