Catastrophic failure will hit you for a large chunk of your hp and cause the tinker to incur a 6 hours CD.
The polymorched, confused, etc is a normal failure which the critical failure prevention unit doesn’t pervent.
If you already have engineering procession, you can have a perk from specialization that prevents catastrophic failure. In that case the reagent that reduces failure chance the chance by 15%
What happened to you was a regular malfunction not a catastrophic malfunction. I know that a tank getting polymorphed in combat is usually is what you consider catastrophic, but this is not what the term “catastrophic” means in game.
A catastrophic malfunction (which the critical failure prevention unit prevents) would cause you to take a large chunk of your HP as fire damage (in combat it’s high likely to kill you when combined with other sources of damage) AND incur a 6 hours CD on the tinker.
Yes.
It malfunctioned because it has a chance to. As I said above, the [Critical Failure Prevention Unit] prevents only catastrophic malfunction.
There is a post on wowhead that says different qualities of the tinker affect the cast time and the chance, but he says he got the information from a youtube video (he didn’t link the video).
The cast time is easy to test in game. The success chance is harder to test because you need to test many times to get reliable data.
The following outcomes occurred to me based on my own experience with the neltharion breath tinker (I don’t use the CR one because I play druid):
- Polymorph
- Getting reduced in size
- Running at high speed forward for a few seconds (can cause you to run into a trash pack and aggro it or into fire, or whatever)
- incapacitate / stun
The DPS from the breath tinker is not that big unless pulling a big pack of mobs, but I used to activate the tinker in town whenever it’s off CD because it has a chance to make me discover failure reagent recipes.
There aren’t enough information in game apart from what you see in the tooltips. Google searches and wowhead has some reports from player experiences, but not actual reliable data.
For a non-engineer it’s situational.
For example a healer in a boss fight dies and there is no way your group can kill that boss without a healer. You have two options:
- Wipe
- Use Engineering CR and risk it failing and wiping. Even if at 90% failure rate, it’s better than a 100% wipe.
As an engineer it’s not that bad.
- There is perk “mechanic mind - inventions” 0/40 that prevents catastrophic malfunctions (means you no longer need [Critical Failure Prevention Unit]).
- There is another perk in “mechanic mind - inventions” 30/40 that reduces the chance of failure. The tooltip doesn’t say by how much.
- There is another perk in “Optimized efficiency - generalist” 35/40 that also reduces the chance of failure. The tooltip also doesn’t say by how much.
- There is a reagent [calibrated safety switch] that reduces the chance of failure by 15%. This is the only thing that has an actual number in the tooltip, but it doesn’t say 15% of what. So if the chance to fail is 20% for example, will it reduce it to 5% (20% - 15%) or will it reduce it to 17% (20% * 15%). We don’t know the initial chance to begin with, and we don’t know if it subtracts or multiplies. Different qualities of the reagent affect only recipe difficulty when crafting.
- An engineer can have two items with tinker (googles/bracers). There is a [Tinker: Grounded Circuitry] that you can use in the other slot (googles or bracer) which guarantees success. This tinker never failed for me (but may be it can fail, I don’t know) and it doesn’t incur potion CD. You can use that before using CR. That tinker has lower CD with higher quality (45min/30min/15min). The CD is reset when you start a new M+ meaning that you can use CR reliably 1-2 times in a run (depends on when the deaths occur). I read on reddit that using both in single macro may cause the res to fail. To use both separately.
- I don’t know if engineering skill has an effect on the success chance, but I am currently at 100+16 Engineering, and I very rarely have breath failing. I failed more often when my skill was lower (but I also didn’t have any of the perk that reduce failure chance). In previous xpacs, engineering skill had an effect on tinker chances (but the CR device was not a tinker and had 100% success chance in shadlowlands afaik).
I have currently only one of the perks that reduce the chance of failure (need 20 more knowledge to unlock the other one), and the one that prevents catastrophic malfunction and I use [calibrated safety switch]. My engineering skill is 100+16.
I did some testing by going in a mythic dungeon using the tinker, starting the key to reset the CD of the tinker, using the breath tinker, leaving/resetting the dungeon and repeat. I did 18 tests and I was polymorphed only 1 time.
Of course this is not enough data and I need to test a lot more times before it’s reliable, but a 1 in 18 chance to fail is not that bad. When combined with [Tinker: Grounded Circuitry], it means you have have 1-2 reliable CRs in dungeon run, and more unreliable ones with 90% success chance. It’s a lot better than having no CR at all.