
After 4 years, I finally spent some time figuring out how this card works. The maximum damage you can deal is the same as with basic attacks: 1 damage per action. But attacks only deal damage when they hit, and the Kukri increases the odds of hitting, in some situations more than others.
This would be easier with a chart, but lacking that option, here is the INCREASE in average damage per action that the Kukri gives you over a basic attack, using the standard difficulty Night of the Zealot chaos toke pool with one ghoul at your location:
A. Only 1 action used (attacking once only and not using the extra action effect)
- -2 BASE combat advantage over enemy (e.g. 2 combat investigator against a 4 fight enemy): 0.0625
- -1 advantage: 0.125
- 0: 0.375
- +1: 0.1875
- +2: 0.0625
- +3: 0.0625
- +4: 0
B. 2 actions used (attacking twice and using the extra action ability when possible)
- -2: 0.117
- -1: 0.219
- 0: 0.492
- +1: 0.264
- +2: 0.117
- +3: 0.092
- +4: 0.029
C. 3 attack actions
- -2: 0.131
- -1: 0.234
- 0: 0.482
- +1: 0.248
- +2: 0.104
- +3: 0.083
- +4: 0.021
D. 4 attack actions
- -2 advantage: 0.138
- -1 advantage: 0.245
- 0 advantage: 0.50
- +1 advantage: 0.265
- +2: 0.118
- +3: 0.092
- +4: 0.029
As you can see, with this example the extra damage over basic attack tops out at around 0.5 damage per action. The extra damage is mostly due to the +1 combat bonus, and is maximal when your base combat is equal to the enemies fight. The extra action ability does add a bit more average damage (compare A. to B. above), especially when you are at a bigger skill test disadvantage. These statistics are specific to the Night of the Zealot chaos token pool since there are lots of -1 tokens, so this needs to be modified for each situation, but should give you the general idea.
How do these statistics compare to other weapons? The most reasonable comparison would be against another 1-handed weapon with only non-expendable uses, such as the level 0 switchblade, which deals the following extra damage per action over basic attacks:
- -2 combat skill advantage: 0
- -1: 0
- 0: 0.0625
- +1: 0.125
- +2: 0.25
- +3: 0.625
- +4: 0.8125
In this comparison, the Kukri deals a bit more damage (up to about 0.43 extra damage per action) when your base combat is equal to or lower than the enemy fight value (where you are dealing ~0.2-0.8 damage per action), while the Switchblade deals more damage (up to about 0.8 damage per action more) when your combat is higher than the enemy's fight value (where you are dealing up to 1.75 damage per action). So the switchblade is more useful in the hands of a high combat fighter, while the Kukri helps the low combat investigator more.
Others have often compared the Kukri to the Knife, which is more difficult since the knife has a one-time effect. I will just summarize by saying that the extra action ability on Kukri does increase the average damage slightly over knife, so the choice depends on whether you want to have the single powerful knife effect or slightly more damage over time and a weapon that stays in a hand slot.