1 702.12b A permanent with indestructible canât be destroyed. 2  Such permanents arenât destroyed by lethal damage, and they ignore the state-based action that checks for lethal damage (see rule 704.5g). 3  702.12c Multiple instances of indestructible on the same permanent are redundant.
lethal dose. n. (Pharmacology) the amount of a drug or other agent that if administered to an animal or human will prove fatal.
Quick Answer. According to the United States Nuclear Regulatory Commission, the lethal dose of radiation is in the range of 400 to 450 rem. This level of radiation causes death to around 50 percent of a population that has been exposed over a period of 30 days. Continue Reading.