Strategy Tips: More Dice Probability

Probabilities of winning a dice roll in Risk (various die combinations)			Attacker
			one die	two dice	three dice
Defender	one die	Attacker wins	41.67%	57.87%	65.97%
		Defender wins	58.33%	42.13%	34.03%
	two dice	Attacker wins	25.46%	22.76%	37.17%
		Defender wins	74.54%	44.83%	29.26%
		Both win one	n/a	32.41%	33.58%

Here's a chart I got from Wikipedia. According to this, the attacker always has the advantage statistically. This chart excludes the use of 8-sided dice as well.