According to FFG, you can use it in step 6, even if there are no clues in your location.
"Yes, you can use Professor William Webb’s ability on a location with no clues, so long as you can resolve one of its effects. You’d trigger this ability during step 6, as it’s worded as “when” you determine success."
Caveat that I haven't played with this card yet, just finished some research for Grizzled and realized how common and high-impact Hazard treacheries are in Return to the Forgotten Age.
Some notables for that campaign... spoilers follow, but come on, you're not reading the reviews of THIS card if you care about that... Snake Bite, Resentful Wilds, Crypt Chill, Deep Dark, Poisonous Spores, Ants!. Crypt Chill and Ants! can be brutal asset hate pieces. Snake Bite and Poisonous Spores are both notable as Poisoned sources that can situationally be difficult or impossible to avoid. Resentful Wilds and Deep Dark are hit-or-miss, but potentially cost a lot of tempo.
And to top it off, this would be an acceptable, if slightly below rate, health/sanity buffer if the cancel ability didn't exist at all. Guardian gets 3/3 for 3 resources at 0xp, but in an extremely competitive hand slot. Paying 2xp and 1 resource to move that to a much less competitive slot and pick up that treachery cancellation ability seems pretty good to me. Especially in a campaign like Forgotten Age that stresses your health.
Random synergy bonus round - Mark Harrigan still draws a card for cancelling the treachery, since the cancel ability deals 1 damage to the Gear. And you still get your Second Wind / Second Wind extra healing value.
Ils veulent vraiment qu'on joue Wilson Richards ^^ En vrai c'est bien, mais tellement limité qu'à part lui, je ne vois pas qui d'autre pourrait en tirer profit. Et puis faut la trouver, la piocher, la jouer ... Si Wilson était jouable, ok, mais là, à part compenser une faiblesse, ça ne sert pas à grand chose.
It's a bit of a niche interaction, but due to "Fast. Play during any window", this can be used to dodge enemies (generally hunter enemies) under specific circumstances.
The steps for the enemy phase are (as a rough overview):
This means, if you're before another player in player order (you probably want to be lead if you have Taunt (3)). You resolve hunter keywords, moving enemies onto another player at your location (this can also work if, for some reason, other players already have enemies on them). Resolve all attacks against you, then, in the window before resolving attacks against the next player(s), you play Taunt and take all the enemies on to yourself. At this point, those enemies cannot attack you (since you've already resolved attacks against yourself) and are cleared from the other player's threat areas before they can attack those players.
Again, this is a niche interaction, but possibly something worth knowing. The biggest take away is probably that there is only a single window for enemies to attack your investigator, and there is a window between each of those attack windows where shenanigans can happen.
Cool art, cool flavor, paired with a cool mechanic dripping with theme. I like Deliverance.
Deliverance most obviously avoids encounter card draws, where the more players you have in a game the better it is. At 1 player, it saves no encounter draws- at 2 it saves 1, 3 saves 2, and 4 players you save 3 encounter card draws.
Avoiding encounter draws isn't it's only strength though:
The player playing Deliverance is usually better suited to draw encounter cards (high , solid and some enemy control, staples of the Mystic class). Having them absorb the encounter deck can be better for your weaker investigators, for example.
Much like weaknesses, drawing encounter cards earlier is usually better than later. It gets the encounter cards out, leaves less to chance, and gives you a clear two rounds to deal with the fallout of the encounter cards.
With point 1 in mind, this card is clearly intended for an Calvin Wright, but investigators like Agnes Baker, a prepared Gloria Goldberg, Akachi Onyele, Amina Zidane and Father Mateo are great targets too. Again, mystics are really good at the Encounter Deck.
Do I think it's a good card in solo or two player? Not particularly. Three or four players? Yes, Deliverance is a simple and effective method of controlling the encounter deck.
....If you're brave enough to play it.
By the way, this card has a mechanical resonance with the weakness Overzealous that I like. The guy in Overzealous thinks he's the lady in Deliverance, but he actually just drew an encounter and gained surge for no reason.