Many cards that affect a company’s hazard limit are short-events, which upon resolution apply an effect that lasts for as long as specified on the card (or until end of turn, per CoE Digest 31). However, there are a handful of cards, mostly permanent-events, that have a modifying effect upon a company’s hazard limit while they are in play; many of these effects are based on passive conditions, and so the question is what happens to the hazard limit when those conditions are no longer met, or beyond that, what happens when such a card is discarded, returned to its player’s hand, or otherwise removed from active play.
To the first half of the question, when a passive condition is no longer in effect, its resulting effect also goes away immediately (see ICE 33, ICE 515, COE 201, etc.), meaning that if a company’s hazard limit is being affected based on some condition and that condition is no longer active, that particular effect on the hazard limit is removed and the hazard limit reverts to what it would have been without that effect being applied. This type of card would include:
Drums (if the company is no longer at or moving to an Under-deeps site)
Earcaraxe at Home (if the company no longer has a Coastal Sea in site path)
Eyes of the Shadow (if any of the criteria are no longer met)
Gandalf the White Rider (if the company is no longer overt)
Radagast the Tamer (if the company is no longer moving through the correct regions)
To the second half of the question, per the CRF under “Discard” (see CRF 9):
In other words, any effects of a card in play that are modifying a company’s hazard limit would immediately end if the card itself leaves play, reverting the hazard limit to what it normally would have been without the effect (also confirmed in ICE 114, etc.). This type of card would include:If a card leaves active play, including being returned to a player’s hand, it immediately ceases having an effect on play.
Bairanax at Home
Crept Along Carefully
Drums
Earcaraxe at Home
Eyes of the Shadow
Gandalf the White Rider
Going Ever Under Dark
The Great Eye
Power Built by Waiting
Radagast the Tamer
Shadow of Mordor
Finally, it is worth noting that some cards may require that they be discarded from active play in order to modify a company’s hazard limit, such as Daelomin at Home. In these cases, the card’s effect has an active condition of discarding the card, meaning that the effect itself is only initiated if the card is discarded, thus superseding the CRF’s requirement that the card still be in play.
Note that this digest overrules ICE Digest 71 [Q8] and COE Digest 11. [Q1]