[Runequest] POW gain - mechanically?

[Wayne Shaw]

At 04:41 AM 8/28/2008, you wrote:
>RQI and II had the limitation that you could only get a POW gain 
>roll if you had a 90% or less chance of overcoming a target. Can't 
>remember about RQ III though...

I suspect in the end it doesn't matter so much what the chance of 
success is as the fact there's little meaning to the attack.  If you 
were attacking immobile Piles of Power that couldn't respond and you 
only had a 5% chance, the difference would only be in how long it 
took you to get the roll; it'd still be a pretty much painless and 
quick way to do it, same as it would if you could use the normal 
experience system to get checks for shooting at a wall.