The Critical Hit & Fumble decks; how do they impact the game?

[EisenKreutzer]

I bought the decks on a whim earlier this year, and have been debating whether or not to use them for an upcoming campaign.

Are they any good? Do the results from the Critical Hit deck generally produce weaker or stronger results than a critical hit?
What about the Fumbles deck, how does it impact play?

[Know(Nothing)]

We played with both for a long time before shifting to 5th, and the group consensus was that they were really, really fun. Classes that had almost no other in-house means to inflict conditions on enemies suddenly got the chance to every so often. Crit-fishing builds became hilarious. However, we also played with a modified sort of Hero Points/Action Points, that could be used(among a ton of other things) to negate crit-fails, so martial characters were not punished for making the most attack rolls.

They do introduce some strange rules conflicts in some cases, but no more than a creative player might. As long as the DM running things is pretty fair with adjudicating the occasional overlap, they were great. But definitely have an option, for martials at least, to negate the fails.

[Zrak]

The critical hit cards are all over the place, power wise. Some are strictly superior to standard criticals (because they add an effect to standard critical damage), while others only situationally useful at best. Most add an effect, rather than additional damage, and exactly how strong they are is going to depend on how useful that effect is in your present situation; in general, regular criticals are going to be preferable nine times out of ten against standard enemies. The cards really shine against tougher enemies, where the added effects can be more of a lifesaver and the extra damage wouldn't have ended the fight anyhow. My group tended to use them in "boss" battles, to make climactic battles feel more unique and cinematic. The deck is also pretty solid for a GM to use against the party, contrary to what you might expect, since imposing a terrible condition on a PC is usually more interesting and otherwise desirable than killing the character outright with a lucky roll.

Some of the critical fumble cards are pretty rough; they're approximately on par with the critical hit cards in terms of severity, which makes them significantly worse than regular fumbles. I wouldn't really recommend using them. They pose all the balance and verisimilitude problems of standard fumbles (penalizing mundane characters disproportionately, being more of a risk for higher-level characters, &c.), with the added draw back of posing a real threat of killing characters at low levels.

[Pex]

The same way critical fumbles in general impact the game. As for the cards in particular, the fumble deck exacerbates the situation. By getting a fumble you can critically hit yourself. Imagine you're a warrior doing a critical hit against an opponent, the damage you deal. Now imagine you do that to yourself for the audacity of rolling a 1. Another card can have you be dazed for 1d4 rounds. Imagine not being able to do anything for 4 rounds for the audacity of rolling a 1.

[StreamOfTheSky]

The same way critical fumbles in general impact the game. As for the cards in particular, the fumble deck exacerbates the situation. By getting a fumble you can critically hit yourself. Imagine you're a warrior doing a critical hit against an opponent, the damage you deal. Now imagine you do that to yourself for the audacity of rolling a 1. Another card can have you be dazed for 1d4 rounds. Imagine not being able to do anything for 4 rounds for the audacity of rolling a 1.

This. I would never use the fumble deck. I'd probably avoid the critical hit deck, too. The game is randomly lethal and rocket-taggy enough already.

[Zrak]

The critical hit deck actually mitigates the random lethality somewhat, in my experience, since the majority of cards replace the bonus damage with an effect, rather than add an effect onto it.

[Kantolin]

The cards make combat more random, which is almost entirely bad for the PCs. It then only really effects martial units (although it discourages rays), especially because magic fumbles are usually particularly horrible.

The crits tend to be 'you do double damage and this extra effect', although sometimes they are bad to the person who rolled it. This also tends to be rougher on the PCs - once in awhile they'll status the boss who will become nerfed due to it, but most of the time they'll blind 'goblin #4 who has 1hp now anyway'. On the other hand, the boss might not do it, but a couple unlucky blinds and an easy goblin encounter has become a very swingy nightmare that the casters can stand on top of.

The fumbles tend to be pretty bad - usually it's 'Something rather bad happens to you'. Again, once in awhile the boss will fumble and functionally incapacitate themselves, but most of the time it will happen to a PC, or to unlucky goblin#4 who was about to die anyway. This will usually take the PC out of the fight for time ranging between a couple rounds and the rest of the combat.

One of the fumbles is 'You crit an ally in reach automatically', which had a 100% chance of the magus (who did the fumble) murdering the fighter (Who had dropped his weapon and was blind, also due to fumbles). It was a lengthy fight - there were a lot of extremely weak goblins, but they did have existent ACs and the occasional miss chance... resulting in the frontliners being almost inevitably screwed by the end of it. I was a caster during this endeavor and more or less ended up winning with just me and the other caster after the DM more or less threw out the fumble cards. Other gems include weapons breaking, bows snapping, critting yourself, random petrification, and daze for everyone! Also 'your crit dazes the enemy but they get a free crit against you', also dropping the fighter.

In addition, people who swing more often are more likely to fumble. So fighters will botch more often than clerics, and two weapon fighters will fumble more often than power attackers, and higher level characters will fumble more often than lower level characters.

I do not find them to be a fun impact to the game, but many people do.

[Zrak]

Do they really do double damage and an effect? It's been a couple years since I was in a group that used them, but I recall pretty clearly most of them adding an effect to the attack's regular damage, not to critical damage.

[Kesnit]

The same way critical fumbles in general impact the game. As for the cards in particular, the fumble deck exacerbates the situation. By getting a fumble you can critically hit yourself. Imagine you're a warrior doing a critical hit against an opponent, the damage you deal. Now imagine you do that to yourself for the audacity of rolling a 1. Another card can have you be dazed for 1d4 rounds. Imagine not being able to do anything for 4 rounds for the audacity of rolling a 1.

Not being able to do anything for 1d4 rounds? How about not being able to do anything for the rest of the game - maybe multiple game sessions. I don't know if it's the same deck the OP has, but my DM has a deck with the card "your weapon bends. DC 20 Craft to straighten it." So now your melee combatant is in the middle of nowhere with no weapon, no forge (which my DM was requiring), and no idea when the party would get back to a town with a smith. (It didn't happen to me, thankfully. It happened to the PC who mostly uses a bow, but was using a sword at the time. His bow was fine.)

[Chronos]

They also don't differentiate between weapons with different crit multipliers, so it suddenly becomes pointless to use axes, picks, or spears instead of swords.

It's something that could maybe be fun in a system designed to use it, but 3.x/PF is not that system.

[Zrak]

I think the explanation card actually addresses that. On a card that deals normal damage, a greataxe deals 2x rather than 3x, and pick/scythe 3x rather than four. On a card that deals double damage, high critical weapons use their standard modifier.

[Sacrieur]

I'm not a fan of them.

As if you need to reward/punish the player even more than the mechanics already do.