Editing Warhammer 40,000/8th Edition Tactics (section)

===Dice Roll Maths===
*It is almost always better to re-roll dice than to get +1. For instance, re-rollable 4+ has almost a 10% edge over 3+.
**The exception is re-rolling 6's, which is 1/36 worse than 5+.
**Because of how people throw dice, a re-rollable 2+ has a lower chance than math suggests. People tend to use the same rolling motions, which means those dice often end up in the same position ("1" both times). So use a dice tower or roll your dice more thoroughly for a longer period of time in order to increase randomness and adherence to estimated made via mathhammer.
**The only time you want a +1 To Hit instead of a re-roll is with Overcharged Plasma weapons or effects that proc off of 6+'s.
*The average roll on a D6 is 3.5
*The average of 2D6 is 7, 3D6 is 10.5., and 4D6 is 14 (add 3.5 for each die you roll). 
*Picking the highest of two dice adds about 1 (actually .9722....) to the average roll.
*4+ re-roll 5+ is the same as 3+.
*Re-rolling 1s is always equivalent to multiplying your odds of succeeding by 7/6, which means, additively speaking, it's better the higher your original odds are: you'll get an extra success in every 12 dice for a 4+, 9 dice for a 3+, and slightly more than 7 dice for 2+ (actually 7.2).
**Re-rolling all failures has a larger benefit the lower your original odds; you'll get an extra success every 4 dice for a 4+ base, every 4.5 (i.e. 2 successes every 9) for a 3+, and every 7.2 for a 2+.
*The odds of getting a 9 or more on 2d6 is 10/36, a little less than a third (27.78%). Re-rollable, it's a bit less than half (47.84%)
*And, if you're into it, there's [[MathHammer]].
*GW dice are not mathematically fair! This set of mathematical data presumes you are using perfectly balanced casino dice which are. See following for details. http://www.dakkadakka.com/wiki/en/That%27s_How_I_Roll_-_A_Scientific_Analysis_of_Dice
[[Category:Warhammer 40000 Tactics(8E)]]
{{Warhammer_40k_Tactics}}