Can you push or pull allies in Frosthaven?
Only if the ability allows it. A plain Push or Pull is a negative effect and targets enemies; it can hit allies only when the card targets allies or “all figures”.
Targeting is decided by whether an ability is positive or negative. Negative abilities can only target enemies, and positive abilities can only target allies or the acting figure.
Push and Pull on their own are forced movement against the target, so they follow the negative rule and hit enemies. If the card says it targets allies, or says all figures, then allies are fair game.
The one thing that makes this worth knowing: whoever performs the push or pull chooses the direction and distance. When a character pushes, that is the player, not the monster controller.
“In general, negative abilities can only target enemies, and positive abilities can only target allies or the acting figure themselves. … an ability specifying its targets as “all figures” targets both allies and enemies.”
Rules change with errata and with digital patches. If your copy of the book disagrees, the book wins — the official Frosthaven FAQ is the next place to look.