Highstorms and visions
After he began listening to readings from The Way of Kings Dalinar began experiencing strange episodes during each highstorm. As each stormwall hit, Dalinar suddenly felt as though he had been transported to another place. The people he interacted with did not see him, but someone else in his place. The visions felt real to him, as he could feel pain. The visions often depicted places he had never been, nor heard of, or were places he knew of referred to by ancient names. He also saw the fabled Knights Radiant alive and in action. He surmised that the visions were from ancient Desolations during the Shadowdays. Dalinar could not summon his Shardblade in a vision.
At first, Dalinar suffered these visions feeling he was going mad. Dalinar eventually volunteered to be tied to a chair, because he raved and thrashed about. Watching him was unnerving, and Renarin told him that he spoke gibberish during the visions. Though Dalinar thought that the visions might have been sent from the Almighty, he wavered and felt uncertain about them. He spoke to the ardents, but received no solution. Feeling he was losing his mind, Dalinar decided to abdicate his position as Highprince in favor of Adolin. In an argument about this topic, Renarin suggested that they try to prove whether the visions were fabrications or contained any real references. They decided to ask Navani to document the visions.
This decision led to the discovery by Navani that Dalinar did not speak gibberish during his visions. During the first vision she witnessed, he spoke the Dawnchant. They considered this proof that the visions were real. The Dawnchant was a real extinct language on Roshar, but there were no known translation keys for modern scholars to study it. Since Dalinar would have had no prior knowledge of the Dawnchant they came to the conclusion that his mind could not be fabricating the visions. As a side effect, Navani was sure that this discovery would help to translate an old book called Analectics.
In Oathbringer he revisted the visions. He was able to bring other people with him, and that was how he helped build the alliance between the nations. Everytime he entered the visions it would play out a little differenlty. One time, Odium came to him in a vision. After this, they demed the visions too dangerous to use and only went in another time to bring in Venli and try to make a pact with the Voidbringers.
The visions predicate
All of the visions shared the challenge given by an unknown voice:
”You must unite them, the strange, booming words had told him. You must prepare. Build of your people a fortress of strength and peace, a wall to resist the winds. Cease squabbling and unite. The Everstorm comes.—Dalinar's memory from one of the visions
From the visions shared statement Dalinar drew the conclusion that he had to unite Alethkar's highprinces because only then would mankind have a chance to withstand the coming events. The visions led Dalinar to the decision to attempt to refound the Knights Radiant.
Mentioned and recorded visions
During this vision Dalinar found himself in the role of a man, Heb, who lived with his wife and daughter, presumably during the advent of a Desolation. Heb and his daughter were attacked by Midnight Essences, but managed to reach Heb's house unharmed. Two more of these beasts followed, and after Heb (Dalinar) fought them off with a metal fire poker, Heb took his wife and daughter and fled from the house. A short time later they were surrounded by Midnight Essences. When he and his family thought all was lost, two Knights Radiant arrive. One immediately began to fight the beasts, while the second used Regrowth to heal Heb and his family before joining her companion in fighting the Midnight Essences. Feeling good again after the healing, Heb joined the fight, and the three of them fought off the Midnight Essences. The male Knight Radiant asked Heb about his strange fighting stances and invited him to come to Urithiru, where the Knights Radiant were centered because everybody who could fight was needed.
Dalinar mentioned that this was his twelfth vision.
A Highway to the Sun
Dalinar was in the role of a soldier named Leef, at a fortress called Feverstone Keep. He witnessed the Orders of the Windrunners and the Stonewards abandoning their Shardplate and Shardblades, forsaking their duty to the people of Roshar. Though Dalinar tried to get an explanation for their abandonment from the leaving former Knights Radiant, he received none. The voice told him that "this event will go down in history" and Dalinar assumed that he just saw the Day of Recreance.
That Which We Cannot Have
In this vision Dalinar was shown the aftermath of a Desolation. His role was as a man named Karm, an adviser to a king, probably Nohadon himself. This king wavered over what to do with the Surgebinders, and how they could be made to act more honorably. Though this king was younger than Dalinar had imagined Nohadon to be, and refused the idea of writing a book as absurd, Dalinar was sure that he was right about him being Nohadon. The king mentioned that all of his scribes were killed after Yelig-nar broke into his chancery. Eventually this man decided to unite the people so that they could stand better against future Desolations.
In the Top Room
This is the last vision recorded in The Way of Kings. Dalinar found himself in a place that he recognized as the place of his very first vision. A man stood beside him, showing him what might happen in the future, though the man admits that Cultivation is better at seeing the future than he. Then, finally, Dalinar realized that this voice, this man, has never actually heard him, explaining why he never answered Dalinar's questions. This man told Dalinar that he is God, the Almighty and that Odium had killed him.
The Lake Fortress
In Words of Radiance, Dalinar had a vision in which he saw himself as a soldier, marching with several other soldiers through a shallow body of water that he believed to be the Purelake. They were heading towards a massive fortress, which was not known to exist in the Purelake in modern times, and looking for a spren acting unusual. They mention that Sja-anat made spren act odd. Dalinar saw a spren with red eyes, followed shortly by another, larger spren which animated a massive piece of stone, which ripped itself free of the lakebed to attack them. The soldiers mentioned that the beast was a Thunderclast.