Tarantism procs surprisingly often for 10%

[Surt]

Plague Doc got tarantism and would move almost every turn from then on. Dunno if it was a run of bad luck or not, but it ruined that run.

[Pixel Peeper]

First time I had it, the character kept moving. Second time she barely ever moved.

I guess the RNG is just weird on that. More prone to strings than it should be, maybe?

[Jaggid Edje]

I did two full playthroughs with a jester suffering from it, and it barely ever proc'd for me across the entirety of both runs. Sometimes it was so long between it happening that I actually almost had forgotten about it.

[HighLanderPony]

rng is rng

[Divvu]

Let's see. Invert those % and do the math. The average combat lasts 4-5 rnds.

You have 90% of not activating first round
You have 81% of not activating neither the first nor the second
72.9% of not activating in the first 3 rnds of combat
65.61% of not activating in the first 4 rnds
59,049% of not activating ever, in your average combat

As you can see, tarantism makes you character move (or dodge!), on average, at least once every 2-3 fights you take. That's the average. You can easily run into a streak of outliers and move 3 time in a single fight. 10% is deceptively high.