I came across this old fable, which has some useful survival lessons. The lesson is similar to most survival lessons: stay calm, control emotions, do not panic, think things through, take precautions, and act with a good heart. And any self-defense tools are only used in self-defense.
This is the story (altered slightly from the original):
There once was a king and queen of a small kingdom. They were generally well-liked by everyone, but each had one main flaw. The king was naive and easily tricked by others, while the queen was guileful and used a mask to hide her cunning.
What the queen wanted above all else was full control over the kingdom. Like many on the spiritual path, what the king wanted was to leave the kingdom behind and live the life of an ascetic. This made no sense to the queen, who believed the king was trying to get rid of her. So she conspired to have the king locked in the palace dungeon.
Once the king learned of her plan, he enlisted the aid of a medicine man, who then helped him to make a magic spell, a spell which could destroy her mask, the source of all her power. But the king was not mean-spirited and had no wish to use it. He only held it in case the queen tried to hurt him. He summoned his trusted messenger and sent the queen a warning of his desire to depart the kingdom in peace and of his possession of the spell should she try to stop him. The choice was hers.
The queen, ruled by her fear and hatred, immediately had the guards throw the king into the dungeon. He was forced to use his magic spell. The queen's mask disintegrated, allowing everyone to see her deceit and cunning. She lost her advisors, she lost the support of the people, she lost her power and she lost all her riches. In fact, she was thrown into the dungeon, while the king was freed and allowed to continue on his path.
Key rules of survival and good decision-making, applicable to all aspects of life: control your emotions and think things through.