Our opponent just can't fold at showdown and hence we have great implied odds.We don't want to make hard and fast rules here but there are some exceptions vs passive opponents where we can get away with cold-calling these hands for one of the two following reasons in a no-limit-game The exception is that there are already 2 limpers in the pot, in which case it's fine to limp behind some straight-draws and flush-draws, but gut-shots should typically be folded. It may seem attractive to be dealt 4-to-a-straight or 4-to-a-flush, but we usually won't hit them often enough to make up for our preflop investment. In most cases we should avoid drawing to flushes and straights.