Topic: Guide and Penalties To Hit

[Blazinghand]

Background
1. Guide is a power that lets you re-roll failed hit rolls.
2. Some units, like airborne flyers, or certain chapter tactics units, have a rule that says something like "your opponent gets -1 to hit when shooting at this unit" under certain circumstances, like if a certain distance away.
3. The Warhammer 40k Rules Primer on the GW Website (link) tells us that re-rolls "happen before modifiers (if any) are applied."

Scenario/Question
Let's say I have a unit that has Guide on it, which allows it to re-roll failed hit rolls, and it is shooting at something with the Hard To Hit rule, so it gets -1 to hit. The unit's base Ballistic Skill is 3+, meaning that under normal circumstances I would hit on a 3+. If I roll a 1 or a 2, this is obviously a miss and I re-roll using Guide. If I roll a 4+ it's clearly a hit. However, if I roll a 3, it is a miss, but only after applying the modifier from Hard To Hit. Am I allowed to reroll a 3 using Guide?

Re-rolls, we must remember, "happen before modifiers" which means that the 3 might not qualify as a "failed hit roll" at the time we do re-rolls, meaning it is not eligible for Guide.

However, it seems pretty silly that Guide wouldn't allow this to be re-rolled.

How does this work?

[Lord of Winter and War]

So, yeah it's a bit silly. Modifiers all happen after re-rolls.

So, you guide a unit lets say and they move and fire a heavy weapon. So, they are -1 to hit, but re-roll all failed hits. Lets say their BS is a 3+

So, Roll (lets say five shots) and the results are a 1,2,3,3,6

As you're BS 3+, you can re-roll the 1 and the 2 with guide.

After re-rolls, Lets say you now have a 1,3,3,4,6

Next, the modifiers come into play, so BS 3+ becomes a 4+ so anything above a 4 will hit, so you discard the 1 and both 3's.

In the end, you have 2 hits.

[magenb]

yeah guide isn't very useful unless you've got a big unit of something like reapers.

[Blazinghand]

interesting, makes sense. Thanks!

[Gal'rgae Neverborne]

Background

3. The Warhammer 40k Rules Primer on the GW Website (link) tells us that re-rolls "happen before modifiers (if any) are applied."

I was just logging in to pose a similar question, and it is black and white. And being FAQed means it's unlikely to change.

I was thinking about why we have this, this way, is it an oversight?

Looking for any game theory guru's input on this?

As I can see it is a crazy.

If you have a positive modifier lets say 3+ to 2+ you then need to roll your '2s' again!

And of course, if you have a 3+ to 4+ due to a -1, you can't re-roll your 3's.

Seems unnecessary. Anyone help with the method behind the madness? Seems very much 'unsimplified'.

[Lord of Winter and War]

Personally, I find it a great way to tone down re-rolls, which are really powerful right now.

[Gal'rgae Neverborne]

Looking more into this,

Could you elect not to re-roll your dice, or are you forced to?

Is the intent to prevent 2+ re-roll ables?

Any rule theory guru's out there?

[Blazinghand]

Looking more into this,

Could you elect not to re-roll your dice, or are you forced to?

Is the intent to prevent 2+ re-roll ables?

Any rule theory guru's out there?

If a model has ballistic skill 2+ and also is allowed to reroll 1s then it can. This will help 35 out of 36 shots connect. The rules clarification we are talking about only applies when there is a penalty to hit. Examples will include scenarios like night fight or moving and firing a heavy weapon.

[Gal'rgae Neverborne]

I'm not sure it's a simple as that. In the case of 3+ modified to 2+

If you had to reroll your 1s and 2s it's not 35 out of 36 anymore. I'm not a maths Guru but I think the fact that in the first round of rolls if you were forced to re-roll your 2s the odds would be slightly worse.

[Lord of Winter and War]

Looking more into this,

Could you elect not to re-roll your dice, or are you forced to?

Is the intent to prevent 2+ re-roll ables?

Any rule theory guru's out there?

Why would you not want to re-roll dice? Also, there is only a penalty if you have negatives to hit. Positives to hit doesn't effect anything.

[Gal'rgae Neverborne]

As mentioned in the OP comments.

You apply modifiers after re rolls

This means that if you are a 3+ to hit with a +1 modifier, your 2s would count as misses and if you had to reroll all your misses they would be included.

You could avoid this by as mentioned electing not to re-roll your 2s which would then become hits after re-rolls applied.

Imagine the following you roll 6 dice, with BS or WS 3+ unit with buff giving them 1+ to hit and another buff allowing them re-rolls to hit. (say a unit of 20+ blood letters within 6" of Skarbrand)

Your rolls are 1,2,3,4,5,6.

Now you need to take your re-rolls, as the unit hits on 3+, (the +1) not applied yet

You then take your rerolls (1,2) (the 2 is at this stage a miss) and roll (1,1)

The 2 would have been a hit without the reroll but as you've re-rolled it you have a 1 in 6 chance of rolling a 1.

You, therefore, check to see if the rule states "may" or "can" as opposed to must take re-rolls.

Instead, you elect to re-roll only your (1) and not to reroll your (2)

After your reroll has taken place you then apply your modifier, the 2 becomes a hit at this stage.

[Blazinghand]

I'm not sure it's a simple as that. In the case of 3+ modified to 2+

If you had to reroll your 1s and 2s it's not 35 out of 36 anymore. I'm not a maths Guru but I think the fact that in the first round of rolls if you were forced to re-roll your 2s the odds would be slightly worse.

I misunderstood. This situation you described is not "2+ Rerollable" it is something else. Let me describe how the rules work in situations like this:

Scenario A: Model has Ballistic Skill 2+, and is going to move and fire a Heavy Weapon, giving it -1 to hit. It has an ability or is affected an ability that says that says "you may reroll all misses"

In Scenario A, you roll a d6 to hit and you get a...
1: You MISS, so you can re-roll.
2: Unmodified, you HIT, so you don't re-roll, and after modifiers you MISS.
3. You HIT.
4. You HIT.
5. You HIT.
6. You HIT.

Effectively, this is "3+ to hit, rerolling 1s" which will hit about 7/9 of the time.


Scenario B: Model has Ballistic Skill 4+, and gets +1 to hit from a special rule. It has an ability that says "you can reroll all misses"

In Scenario B, you roll a d6 to hit and you get a...
1: You MISS, so you can re-roll.
2: You MISS, so you can re-roll.
3. Unmodified, you MISS, so you CAN re-roll if you want. However, you choose not to, because you know that after the modifier this is a HIT.
4. You HIT.
5. You HIT.
6. You HIT.


In other words, with a positive modifier, sometimes you choose not to take rules that you rules-wise have the option to, specifically when the unmodified roll is a miss, but you know that with modifiers it would be a hit.


It's all very simple, in my opinion: look at the raw unmodified die roll to determine whether or not you can re-roll, and use the modified die roll at the end to determine whether or not it is a hit.

[Gal'rgae Neverborne]

You've got it!

And if you had a rule which allowed you to re-roll hits and misses (not sure if that exists) you could neutralise the staging problem totally.

[Blazinghand]

You've got it!

And if you had a rule which allowed you to re-roll hits and misses (not sure if that exists) you could neutralise the staging problem totally.

Earlier in this thread someone noted Cawl has this ability but otherwise that wording is rare.