Hope this isn't on here already, I never looked. Basically just as it sounds. Defensive spells based much like what the spell factory is, and you place them ONTO a building or wall in your village. When that building is attacked, the spell activates. Possible ideas that I like.
1. Slow Field - Radiates a ten tile area of slowing for a time. Makes all enemies inside the field move and attack significantly slower.
Upgrades: 5 levels, 1-5 gives slight time increase, with level 5's ultimate being an additional two tiles, for a total of circular twelve.
2. Vampiric Field - The building that holds this field drains life from all enemy units in a three tile area, giving 80% of it back to the building and leaching it away from the units themselves. Only lasts a short time, three seconds at level one, but the DPS per unti would be about 10, so the more units it hits at once, the better it works.
Upgrades: 5 levels, with 1-5 only adding a second of time, with level 5 giving an additional tile for a total of circular four.
3. Knockback Field - Generates a three tile force-field of sorts that shove all units, flying and other wise, 4 tiles away from the area of effect. (a dragon starts attacking a building in air at range while at the same time a barbarian starts hitting the same building. Both units are pushed a total of 7 tiles away from the building and experience a 1-2 second lag time where they don't attack.)
Upgrades: 5 levels, with 1-5 increasing damage done to all units affected by a small margin, with level 5 giving a 3-5 second lag time for affected units depending on spell level verse unit level.
4. Mirror Field - Only affected by ranged attacks, any and all ranged attacks (after the initial) are deflected back towards the enemy that shot it. It takes a full two seconds to power up and activate though, so if a large enough group of archers or dragons can provide enough DPS within that two second timer to destroy the building, then it's destroyed and the spell does nothing. If the spell is activated, the returned shots do full damage either to the ranged attacker OR to a melee unit attacking the building. (barbarians and archers both begin attacking a building, the mirror field activates and that arrows begin to hit the barbarians. If the barbarians are killed before the field wears off, the ranged attacks then begin to attack the archers.)
Upgrades: 5 levels, with 1-5 increasing by .5 seconds the amount of time the field is active and level 5 decreasing the two second activation delay to 1 second.
5. Chain Lightning - the first attack done to a building activates a single charge of chain lightning, dealing damage to all units the lighting chains to (on a diminished value for each transfer) and stopping each unit hit for 1 second.
Upgrades: 5 levels, 1-5 giving an additional unit(s) to be added to the chain and a slight damage increase. Level 5 also increase the lag time for affected units from 1 second to 2 seconds.
Feedback is appreciated.



