Interestingly, this story only contains two characters, and both are so similar in terms of their traits that they would be hard to distinguish from each other. The only thing that seems to separate Georg Znaeym and Ulrich von Gradwitz is the implacable and personal feud that the two rival families have been raging against each other for many years. Apart from the similar traits of hatred and revenge therefore, these two characters are not given any characteristics that we could use to differentiate them from each other, except for their names. Note what happens and how they feel when they meet:
The two enemies stood glaring at one another for a long silent moment. Each had a rifle in his hand, each had hate in his heart and murder uppermost in his mind. The chance had come to give full play to the passions of a lifetime.
Even after the tree falls, pinning them both to the ground, this hatred remains as they talk about how they will kill the other when their men arrive to help them, showing their ruthless nature and how they are obsessed with hatred. Of course, just as they are united in hatred, the disaster that has befallen them both also gives rise to a change of heart in them as they make peace:
For a space both men were silent, turning over in their minds the wonderful changes that this dramatic reconciliation would bring about.
Thus the two characters, in terms of their traits, are united together in hatred, and then in peace, before the unfortunate end of the story.
Ulrich von Gradwitz and Georg Znaeym are enemies. Their families have been feuding for years over who should rightly own a strip of forest. Gradwitz' grandfather gained rightful ownership through the courts years ago, byt Znaeym will not give up thinking he has rights to the land.
The feud might, perhaps, have died down or been compromised if the personal ill-will of the two men had not stood in the way; as boys they had thirsted for one another's blood, as men each prayed that misfortune might fall on the other, and this wind-scourged winter night Ulrich had banded together his foresters to watch the dark forest, not in quest of four-footed quarry, but to keep a look-out for the prowling thieves whom he suspected of being afoot from across the land boundary.
From this quote, you can see that these two men hate each other. Ulrich is literally hunting for Georg Znaeym. He plans to shoot him when he finds him. Likewise, Georg is planning to shoot Ulrich. They are planning to find an offence from the other so as to have a reason to shoot the other one. They run into each other in the dark of night in the woods:
The two enemies stood glaring at one another for a long silent moment. Each had a rifle in his hand, each had hate in his heart and murder uppermost in his mind. The chance had come to give full play to the passions of a lifetime. But a man who has been brought up under the code of a restraining civilization cannot easily nerve himself to shoot down his neighbour in cold blood and without word spoken, except for an offence against his hearth and honour.
When lightning strikes a tree and the tree falls on both men, they are pinned down within touching distance of each other. They finally communicate and decide to end their feuding:
Neighbour," he said presently, "do as you please if your men come first. It was a fair compact. But as for me, I've changed my mind. If my men are the first to come you shall be the first to be helped, as though you were my guest. We have quarrelled like devils all our lives over this stupid strip of forest, where the trees can't even stand upright in a breath of wind. Lying here to-night thinking I've come to think we've been rather fools; there are better things in life than getting the better of a boundary dispute. Neighbour, if you will help me to bury the old quarrel I - I will ask you to be my friend.