It looks like an old 3.5e weapon, the x3 would have been the damage multiplier in the event of a critical hit.
So transferring to 5e the damage would be 3d6+6 on a hit and x2 damage ona crit.
EDIT: if you see a weapon stats in the fomat of "d6+1 / (19-20) x2" the numbers in the brackets were the critical threat range of a weapon, so a (19-20) would of scored a crit on a natural 19 or 20.
Hey so here is my issue
Im using a slightly older book for monsters and one of the stat sheets had a great weapon attack written as follow
(3d6+6/x3)
So does that mean
3 d6, +6 for each of those dice, then multiply by 3?
I'm confused caus the monster had a CR of 4 and I'm like that is stupid broken. I'm new to DMing and I'm a bit lost
It looks like an old 3.5e weapon, the x3 would have been the damage multiplier in the event of a critical hit.
So transferring to 5e the damage would be 3d6+6 on a hit and x2 damage ona crit.
EDIT: if you see a weapon stats in the fomat of "d6+1 / (19-20) x2" the numbers in the brackets were the critical threat range of a weapon, so a (19-20) would of scored a crit on a natural 19 or 20.
I'd read the entry, see if there's anything similar in the 5th Edition, and use that. Converting Olde Stuff is more work than it's worth usually.
<Insert clever signature here>