- Some components are designed to offer small chances of catching a mouse regardless of the mouse’s strength. It is not uncommon for lucky traps to grant hunters the ability to catch mice that seem far too powerful for their trap.
Luck is a trap attribute that gives the player a chance of catching a mouse even if it would have normally gotten away. It works independently from the power and power type of a trap. Luck does not affect the attraction of mice, but as of April 2009, it also has a small effect on loot dropped by mice. Additionally, hunters who complete special offers or donate for SUPER|brie+ receive an additional 7 luck added to their trap's luck and a Golden Shield on their Hunter's Profile page for 30 days or more.
Details of luck
The Developers mentioned (around the 14 minute mark in a video from 13 March 2009) that luck is nonlinear, so the more luck you have, the more effective it becomes. Hence 8 luck is more than twice as good as 4 luck. Moreover, they also mentioned that it is more effective against a stronger mouse than against a weaker mouse, so 4 luck against a stronger mouse has more benefit than 4 luck against a weaker mouse. Luck works almost like a separate roll (see Hunting Sequence), so that regardless of a trap's power and power type attributes, a mouse can be caught based on pure luck.
The Developers also mentioned that 7 luck bonus "equates vaguely to approximately having one less failure to catch a day" and, regarding loot drops, that "20 luck will increase your odds by less than 2% for most items in the game."
Most recently, developer Dave has said that "The equation that governs luck is designed to be extremely random and streaky. Hunting with crunchy cheese in Derr attracts some of the most hard mice to catch in the entire game. Expect mixed results when relying on luck rather than power."
The seven weapons with the highest luck are the limited edition Chrome DeathBot, Snow Barrage and Chrome DrillBot, with 30, 28 and 26 Luck respectively, and the PartyBot, HitGrab Rockin' Horse, 2010 Blastoff Trap and HitGrab Rainbow Rockin' Horse, all of which have 25 Luck. `The weapon with the highest luck that is not limited edition and currently available to players is the Arcane Capturing Rod Of Never Yielding Mystery, with 18 Luck.
The base with the highest luck is the limited edition Magma Base, having 10 luck, followed by the Aqua Base and the limited edition Candy Cane Base, both with 8 luck. Thus the highest possible luck value in-game is 47 Luck, pairing the Chrome DeathBot (30 Luck) with the Magma Base (10 Luck) and the golden donor's shield (7 Bonus Luck).
Without implementing limited edition trap components, the highest luck value possible is 33 Luck, using the Arcane Capturing Rod Of Never Yielding Mystery (18 Luck), the Aqua Base (8 Luck) and the golden donor's shield (7 Bonus Luck). Without the bonus luck from the Golden Shield the same setup yields 26 Luck, making it the trap with the highest luck available to all players without requiring donations, the completion of offers, or the use of limited edition trap compone
The Developers mentioned that luck is the least important trap attribute broadly speaking, and because power works much more often than luck does, hunters should generally not neglect significant differences in power or power type in favor of boosting luck. However, there are exceptions.
The PartyBot, for instance, is a generally effective trap for the Mousoleum, partly because of its luck, even though many of the mice there don't match its power type. Before the Ancient Box Trap was introduced, it was necessary to set up a trap with the highest luck when hunting the Acolyte Mouse, since there was no trap that matches its power type and it was so difficult, thus luck was the only tool available. Without a Forgotten type weapon, if the hunter is specifically trying to catch an Acolyte, the hunter can maximize his or her odds by using the luckiest trap setup available, though it may come with a lot of misses on the Forgotten Mice that also dwell in the Acolyte Realm if that trap is not of the Arcane power type.