This is a system of magic. Actually, it is more a style of magic. Any magic system can be used with it, but they now follow slightly different rules.
1) All magic spells are anchored to items, a spell matrix is embedded to the item. These could be wands, staffs, rings, cloaks, nicknacks, gems, boots, any item appropriate. This is a moderately short process measured in hours or days.
1b) These are not magic items. They do not provide magical abilities. They allow someone who knows the keys to it to use the spell. Though there will be a minor penalty for lack of attunement to the item.
1c) Encumbrance and availablity becomes as issue. Do you have the right item for the effect you want to cast? Can you carry everything you want?
2) To anchor a spell in an item requires a mystical research task, time and personal effort.
2b) The more effects anchored in an item, the greater the difficulty to anchor more. Each item past the first is a negative MOD to die rolls. You will need to adapt it to your system, but a -3 mod for 1-20 scale roll for example.
2c) Type of objects will provide modifiers. Magical tools (Staves, Wands, Athames, Cups, Disks) give pluses. Metal objects are base. Jems, fewer slots more effect. Cloth lesser, unless there is a pattern woven in, minuses. Paper and temporary objects, pluses.
3) Spells still require other ritual actions to cast (Time, Voice and Gesture), i.e. the casting of the spell.
3a) Additional rituals for the same spell can reduce certain requirements.
3b) Enough rituals and the item can be set to be triggered.
4) Magik items would need instruction books. If the item was usable by just anyone, what would stop people from just stealing your stuff besides your ire? The fact they can’t use it without the right trigger words
To play this magik system would require
a)Some basic spell effects to be built up upon. Missile, Move Object, See Other place. All of these things would form the foundation of effects.
b)A list for the cost of modifiers for basic spell effects. Increasing or decreasing time by steps costs points for example. Additional points required to be the second spell or third spell. If these are not point systems cost modifiers, then they should impact level of effect OR modifier to spell casting rolls.
c)Enchanting skills per type. Some of them for power and some for metamagik (duration, etc)
d) A task system for generating effect points. Effect points are used to purchase spells. Base points would be based on the INT MOD or INT divided by 5
e) An effect point system allowing you to take a basic effect and tweak it up or down.
g) Keeping track of downtime becomes important. There should be fatigue modifers if you spend all your time installing spells.Designer Notes
Hero System, or similar point to effect systems, would be good for this kind of magic. It would even require less work, as this system of magic would just be a bunch of required modifiers. You could take the basic power effects, and list the modifications to make the base spells. You will need to work on the modifiers to better fit the world view. Gurps and Silloute Core would also be functional for this system.