**SpuriousMilius** | **08 Mar 2018** 8:50 a.m. PST |

Many skirmish level wargame rules add 1 or more D6 or D10 to a figure's rolls for shooting or melee to represent skill level or tactical circumstances; others confer 1 or more rerolls to do this. Is either method more of a boost to a successful result than the other? I must have hit the submit button before I completed my question. Sorry |

**USAFpilot** | **08 Mar 2018** 9:09 a.m. PST |

For mathematical problems, the first step is to clearly define the question before seeking a solution. Can you give a little more detail, or an example? |

**advocate** | **08 Mar 2018** 9:37 a.m. PST |

If there is no difference with respect to the number of successes, then no. With re-rolls you roll in succession until you get a success or run out of dice. With additional dice you roll them altogether and check to see if at least one succeeds. If you are looking for anything but a one, re-rolls might be better. In general rolling a together is probably faster. |

**Lupulus** | **08 Mar 2018** 9:51 a.m. PST |

If the result is just success/failure, there's no difference. If you can re-roll a success into a better success then +1 is better (because there is no risk a success becomes a failure) |

**wakenney** | **08 Mar 2018** 10:16 a.m. PST |

There is a difference if the test counts the number of successes. By simply rerolling one die, you can never succeed more times than the base amount of dice. Rerolling 1 out of 5d6 will still only allow for 5 maximum successes. Adding a die adjusts that maximum number, making 5d6 to 6d6. Now, for total probabilities… |

**robert piepenbrink** | **08 Mar 2018** 10:17 a.m. PST |

I'm with USAFpilot. If each die is either a successful accomplishment or not, and the whole thing is either one success or a failure, than Lupulus is correct, but we don't know that. If I need a cumulative score, that's quite a different matter. An added die makes things possible which could not be done if I had a re-roll instead. Spurius, can you help us out here? |

**Dynaman8789** | **08 Mar 2018** 10:23 a.m. PST |

The answer is yes and yes and it depends entirely on the specifics. Sometimes extra dice are better and other times rerolls are better. |

**wakenney** | **08 Mar 2018** 10:47 a.m. PST |

Except in the edge case where you need to get a certain number of successes and adding the die makes it possible, say you need to roll 5 6s but you are only rolling 5d6, there is no real difference. If you are rolling 6d6 and just trying to get one 6, then unmodified you have a 0.66 chance of success. With adding a die or rerolling you have a 0.72 chance of rolling at least one 6. In a situation where the number of 6s matter, on average you are going to roll one 6 out of your 6d6. With adding a die, 7d6, or rerolling one you end up with 1.16 6s on average. |

**Thomas Thomas** | **16 Mar 2018** 9:50 a.m. PST |

Which method you use depends on what your trying to simulate. Games often add an extra die for "stationary fire". This makes little sense as a tank for instance can blaze away while moving but with little chance to hit. So its not ROF that's effected its accuracy. So it would be better to re-roll than increase die numbers (even better to just give an accuracy modifier to the roll rather than a clumsy re-roll. Modifiers move at the speed of thought not so dice rolling). Thomas J. Thomas Fame and Glory Games |