A gas spore, e, is a monster that appears early in NetHack. It is the weakest of the spheres, cannot attack on its own, and is rather slow; however, it acts as a "living mine", exploding in a small radius when its HP is depleted.
It is perfectly fine to simply avoid attacking gas spores altogether, as they are incapable of attacking you. However, other monsters may accidentally cause a gas spore explosion with ranged attacks or an attack prompted by conflict; pets in particular will begin attacking gas spores once they are high enough level, which may endanger you if you are not similarly high-level.
The best strategy when faced with a gas spore that you can reasonably fight (or else cannot avoid) is to step back and use whatever ranged attacks you have at your disposal - offensive spells, arrows, darts, or even throwing rocks and junk weapons. If you have no other options, no peaceful or tame monsters are nearby, and/or you have more than 24 HP along with a good AC, you can take a chance and dispatch the spore with melee attacks.
Early-game Healers can use gas spores to train their skills, such as the knife skill (with the starting scalpel) or the more common dagger. They can use a stethoscope to monitor the gas spore's HP and allow it to heal back up before attacking again; while any class can do this, Healers are the only one guaranteed to start with the stethoscope.
The gas spore's explosion does anywhere from 4 to 24 points of damage, making it a potential game-ending danger for early characters. The gas spore explodes when its HP is reduced to 0; if its death is from deadly poisoning, a death ray, or another effect that does not cause hit point loss, it will not explode.
You are responsible for any damage done by a gas spore explosion that you cause. This has a number of repercussions depending on the monster that has been damaged:
- Pets killed by the gas spore explosion are treated as if you had killed them directly, i.e. -15 alignment and -1 luck.
- Peaceful monsters become angry at you. Shopkeepers, aligned priests, watchmen and other "always peaceful" monsters in that vein will cause you plenty of grief.
- However, other hostile monsters can be killed by the explosion; as you gain experience for each kill, this can possibly allow you to rise a quick level or two if the opportunity arises.
The attack by those who want to die
-- this is the attack against which you cannot prepare a perfect defense.