The TH process uses a lot of technical terms for different numbers. With the Vehicle Target Type and the Area Target Type you can generally be sloppy applying the different numbers and still get the right answer. With the Infantry Target Type (ITT) you have to use the terms and numbers correctly to get the right answer for critical hits.
There are two To Hit (TH) numbers. The first TH number is the
base TH number. That is the number you read off the C3 table by cross-referencing Target Type and Range and black/red TH numbers. The second is the
modified TH number is the base TH number plus the modifications on the C4 table. These modifications are for gun barrel length (*, L & LL), ammo type (APDS/APCR & SMOKE) and gun caliber (≤ 57 mm, ≤ 40mm) as adjusted by range. For most ASL To Hit attempts the modified TH number is the same as the base TH number. The SMOKE modification is perhaps the most commonly applied. The others are not applied that frequently because they only come into effect at ranges > twelve hexes, and most ASL TH attempts are at ranges ≤ twelve hexes. Unless you are firing at long range or SMOKE, the base TH number will be the same as the modified TH number.
You must certainly note that up to now that I have
not mentioned a lot of things that apply to the To Hit process, and those things are the TH DRM (To Hit Dice Roll Modifiers), things like BU, changing CA and FFMO, to name a few. That is because these do not apply to the To Hit numbers. They are modifiers to the To Hit Dice Roll (DR). There are two To Hit Dice Rolls, the
Original To Hit Dice Roll and the
Final To Hit Dice Roll. The Original To Hit DR is the sum of the numbers you read off the dice. The Final To Hit DR is the Original To Hit DR plus any Dice Roll Modifiers.
A critical hit on the Infantry Target Type occurs in two cases (ignoring improbable hits and TH attempts where only a snakeeyes would hit):
- The Final TH DR is < half the modified TH number
- If not 1), the Original TH DR is a snakeeyes and a subsequent dr is a one or ≤ half the modified TH number.
Some quick examples:
A Gun is firing at range six hexes at a squad in open ground. Its base TH number is eight and its modified TH number is also eight. It rolls an original three and there are no TH DRM, so its final TH DR is equal to its original TH DR, three. Since its Final TH DR is < half its modified TH number (eight) the hit is a critical hit.
A Gun is firing at range six hexes at a squad in woods. Its base TH number is eight and its modified TH number is also eight. It rolls an original three with a +1 TH DRM, so its final TH DR is equal to four. Since its Final TH DR is not < half its modified TH number (eight, and the original TH DR is not a two) the hit is not a critical hit.
A Gun is firing at range six hexes at a squad in woods. Its base TH number is eight and its modified TH number is also eight. It rolls an original two with a +1 TH DRM, so its final TH DR is equal to three. Since its Final TH DR is < half its modified TH number the hit is a critical hit. The TH DR is also a two, so the second ITT critical hit criterion might also apply, but since the attack is a critical hit by the first there is no reason to use the second.
A Gun is firing at range six hexes at a squad in stone building. Its base TH number is eight and its modified TH number is also eight. It rolls an original two with a +3 TH DRM, so its final TH DR is equal to five. Since its Final TH DR is not < half its modified TH number the hit is not a critical hit based on the first critical hit criterion. Because the TH DR is an original two, a subsequent dr is made, and if that subsequent dr is one or ≤ half the modified TH number, the hit is critical, and otherwise it is normal. Here the modified TH number is eight, so the dr has to be ≤ four to get a critical.
A 37* Gun is firing at range eighteen hexes at a squad in woods. The particular Gun uses black TH numbers. Its base TH number is six, and its modified TH number is a three (-1 for each * Gun length, Gun caliber ≤ 57mm, Gun caliber ≤ 40mm, all at range eighteen). It rolls an original two with a +1 TH DRM, so its final TH DR is equal to three, a hit. Since its Final TH DR is not < half its modified TH number the hit is not a critical hit based on the first critical hit criterion. Because the TH DR is an original two, a subsequent dr is made, and if that subsequent dr is one or ≤ half the modified TH number, the hit is critical, and otherwise it is normal. In this case the modified TH number is two, so the subsequent dr has to be ≤ one to get a critical.
In order to get the Infantry Target Type critical hit correct, you have to keep your base and modified TH numbers and original and final TH DRs straight and separated. You can't apply the TH DRM to the TH number to get a "final TH number." That won't produce the right answer in many cases.
JR