Now I know how Dirk the Daring felt. Last night I was playing Baldur's Gate when I reached the Thieves' Guild level. There I was confronted with a chasm, and the only way to cross was to leap across a series of floating stones. Only the stones had the disturbing tendency to drop (like a rock!) into the chasm, taking me with them. It was already too late, so while I was analyzing the stones for patterns of collapse, and trying to move faster, slower, and what not, I overlooked the obvious, that the stones would flicker before they began to fall.
Today after lunch I took another stab, after reading the above clue on GameFAQs, and made it across in only a few tries. Then the suckers confront me with another chasm, more than twice as wide. That one took longer, but not as long as the previous night. Now I'm merrily trolling along whacking thieves and spiders (and bugbears, oh my!) while trying to preserve my strength for the boss 'monster' of this level, the Thieves' Guild leader.