To get a basic idea about your odds I made a simulation program to find out what your odds are of winning a roll. For example the first square says that if you attack with 2 dice against 1, you have 83% chance of winning. Each square is a result of 1,000,000 rolls, and if I do it again I get the same results (so it's accurate)
<table><th></th><th align=left width=30>1</th><th align=left width=30>2</th><th align=left width=30>3</th><th align=left width=30>4</th><th align=left width=30>5</th><th align=left width=30>6</th><th align=left width=30>7</th><th align=left width=30>8</th><tr><th>2</th><td>83</td><td>44</td><td>15</td><td>3</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><th>3</th><td>97</td><td>77</td><td>45</td><td>19</td><td>6</td><td>1</td><td>0</td><td>0</td></tr><tr><th>4</th><td>99</td><td>93</td><td>74</td><td>46</td><td>22</td><td>8</td><td>2</td><td>0</td></tr><tr><th>5</th><td>99</td><td>98</td><td>90</td><td>71</td><td>46</td><td>24</td><td>10</td><td>3</td></tr><tr><th>6</th><td>99</td><td>99</td><td>97</td><td>88</td><td>69</td><td>46</td><td>25</td><td>12</td></tr><tr><th>7</th><td>100</td><td>99</td><td>99</td><td>96</td><td>86</td><td>68</td><td>46</td><td>27</td></tr><tr><th>8</th><td>100</td><td>99</td><td>99</td><td>98</td><td>94</td><td>84</td><td>67</td><td>47</td></tr></table>