Effect Trigger

Games Discussion Ars Magica
1

Hello all

I've been mulling magic items in my mind recently and a thought occured. You can have an item trigger by a linked effect. But can you have an effect ENDED by a linked trigger.

Example.
I have an obelisk that casts a light spell on itself every round. I want it to do this until there is a person touching the obelisk.

The linked trigger would be an InCo spell to detect a person at touch range and would be continuous.

The item would thus cast light all the time except when a person touches the obelisk. As soon as the person stops touching the obelisk the light spell starts going off again.

Ignore, if you will, the usefulness of the item, its the mechanics behind it that interests me.

Would this work?

Furthermore could an item have a linked trigger to start it and a linked trigger to stop it?
Could it have several linked triggers to start or stop it?

2

I personally dont see why not...essentially the item is triggered to work when not being touched. Or you could do one of the following...

The trigger may be for a vim spell that surpresses the effect of the constant spell (light in this case)

Or it may be for a spell that does the opposite effectivly canceling the spell (trigger perdo ignem to create darkness)

3

If the primary effect is D: Momentary, with Unlimited Uses, then I would allow the trigger to be automatic, unless someone is touching the stone. I would not require a secondary (or tertiary) linked effect.

If the primary effect has any other Duration, then I would require a secondary power, triggered on touch, to suppress or cancel the effect, as Angar has suggested.

4

I'd rather go for D: Concentration + item maintains concentration. Having a trigger which causes the item to drop the spell seems like a very natural thing to have.

5

With an InCo spell and a linked trigger, I would definatly allow it. I would allow several linked triggers to do whatever you wanted it to do, as long as you're paying for the triggers and have the In spells in the item to trigger them off of. You're paying for it.

6

I guess it would all depend on how many times you want it to go off and on, Most items and effects I can think of i would design the same you you suggested. But you would have to re-trigger it. His suggestion would be good if you want to to automaticaly go back on without being turned on by someone, or didn't want someone to know the 'on' trigger.

7

With that, you still have to consider number of uses, for the effect to restart after you stop touching the device. You are then paying +5 for Concentration duration, +5 to for the device to maintain concentration, +X for the number of times per day the effect can initiate.

A more expensive proposition than simply +10 for unlimited uses at Momentary duration.

However, if you rule that repeated Momentary spells "flicker", then a Concentration duration would be more appropriate.