In Jurassic World the dinosaurs of Gyrosphere Valley roamed around without any physical barrier. Here are my ideas on invisible fence and how to keep it not to overpowered:
First of all, it will only be unlocked when an island's missions are finnished. This will help with issues about using it to get through a mission easily.
Secondly, dinosaurs must be fitted with a radio collar/implant. This will cost some money to add.
Third, power failure causes invisible fences to shut down. They will be restored after the power comes back. If a storm comes that stresses dinos but the power doesn't fail the dinos will try to rip of/out or short circut their collar/implant. They must then be given a new one.
First of all, it will only be unlocked when an island's missions are finnished. This will help with issues about using it to get through a mission easily.
Secondly, dinosaurs must be fitted with a radio collar/implant. This will cost some money to add.
Third, power failure causes invisible fences to shut down. They will be restored after the power comes back. If a storm comes that stresses dinos but the power doesn't fail the dinos will try to rip of/out or short circut their collar/implant. They must then be given a new one.