White Walkers can be added from their pool in 4 ways:

1. Into domains marked on the round’s Ranger Card.

2. Into the Night King's domain and each adjacent domain after he attacks and gains control of a domain (see The Night King Attacks).

3. The result of resolving certain blue Exploration Tokens.

4. Into the domain of the Night King when moving with the Ice Dragon (see The Ice Dragon).

If a player has units in that domain, this immediately results in a battle (see Battling a White Walker). If there are only units of a NP house in the domain, one unit is placed onto the Terror Pool and the remaining units must retreat. If there is already a White Walker in a domain, then the Night King instead gains a Victory Point. There may only be 1 White Walker per domain.

Likewise, if all the White Walkers are on the map and more must be placed, the Night King gains per White Walker that cannot be placed (this is listed on the White Walker Mat). Players may decide in which order they are placed and in which order battles are resolved. If a White Walker occupies a domain with a castle, it does not receive its defense bonus and the castle remains on the map.