30 April 2022

BP-5 Bounding First Fire Mechanics

The Mechanics of Bounding First Fire

By James Bishop and Chris Doary

This article is born out of a recent game. During the match, Jim’s opponent fired the anti-aircraft machinegun (AAMG) on his M36 GMC tank destroyer (TD) before moving to another hex. Upon reaching the new hex, he declared a shot with the TD’s main armament (MA). Only he couldn’t do this. Or more to the point, the rules prohibit it. What followed was a lengthy “rules dive” that reviewed the pertinent sections of Chapter D. The goal was to deepen his knowledge so that he could make the most of vehicular fire in the future. Jim took notes during the conversation, as he thought that the discussion was a good subject for a blog post. Without further ado, let’s dive in.1

A Brief History of ASL Time 

One unique aspect of ASL is that it allows both players to participate in almost very phase, regardless of whose turn it is. Nowhere is this reciprocal activity more apparent than during the Movement Phase (MPh). During the busiest of phases, the non-moving player may pause play to intervene in the actions of a Moving unit, a unit that’s conducting ITS MPh.2 Although the pause may be limited to “stripping” the concealment of a Moving unit, an intervention usually takes the form of a Defensive First Fire (D1F) attack. When and how many times a unit may fire on a Moving unit is nevertheless strictly circumscribed. These limits reflect the transitory nature of a unit’s movement and the brief period of time in which a defending unit has to react to such movements. 

Vehicles, especially Armored Fighting Vehicles (AFV) and their Passengers or Riders, are exceptional in their ability to fire during THEIR MPh. Not surprisingly, vehicles labour under even more restrictive rules of engagement when Moving. Understanding what these restrictions entail is crucial to getting the most value out of these important assets.

The substance of these restrictions can be found in the following rule sections: D3.3, D3.31, D3.32, D3.5, and D3.51. Let’s look at each in turn.3

D3.3 Bounding First Fire

In another recent game, Jim’s opponent wanted to shoot in the MPh. He announced his Infantry Target Type (ITT) shot as an “8 +2 To Hit (TH).” Jim asked him why +2 and not +4? He responded that only the +2  Dice Roll Modifier (DRM) for Case B applied, because he had not moved to a new hex. Jim pointed out that Case B specifically applies to a firer in the Advancing Fire Phase (AFPh), not the MPh. [Ed. I’ve added the slide below to demonstrate Case B in action.]

Click to enlarge

A vehicle that fires during ITS MPh, even one that fires before entering a new hex, is a very different beast. Jim therefore directed his opponent to D3.3. The first sentence tells us that the ASL term for a unit that fires during ITS MPh is using Bounding First Fire, or B1F for short. They continued their discussion with an examination of the C5 Table, which lists Firer-Based To Hit DRM, part of which can be seen in the truncated table below. Jim explained that it was Cases C through C2 that apply to a Bounding First Firer. [Ed. I’ve included Case B for contrast.]

C5 Firer-Based To-Hit DRM

The first thing we should get out of the way is the term Bounding Firer, which applies to a unit that performed one or more actions during the MPh and remains eligible to fire in the AFPh as Bounding Fire.4 What we’re concerned with here, however, is Bounding First Fire, fire undertaken by a vehicle and its Passengers or Riders during THEIR MPh. What Jim’s opponent was attempting to do when he declared an “8 +2 TH” shot is permitted. However, as C5.33 makes clear, Case C does apply in this situation. 

Part of the confusion may lie with the fact that Case C is labelled “Bounding Firer” on the C5 Table. [Ed. I added the word “first” in grey font to the C5 Table.] It’s true that the first part of C5.3 deals with vehicles that have entered a new hex (or hexside) during the MPh and that are using Bounding Fire in the AFPh. But the rule goes on to inform us that Case C also applies to a Bounding First Firer. Case C is essentially an additional penalty for entering a new hex (or hexside) in that Player Turn. As such it can apply during the MPh or the AFPh. Let’s take a closer look at the situation that led to our discussion of B1F, as illustrated in the next slide.

Subcases C1 and C2 simply modify Case C. These penalties are tied to the time—represented in MP expended—that a vehicle has spent in Line of Sight (LOS) of a target. Case C3 is an odd duck given that it’s about firing Light Anti-Tank Weapons (LATW) in the AFPh. In fact, “Case C3 is never applicable to Case C or any of its other subcases” (C5.34). So we’ll skip it. 

That leaves us with Case C4 only the latter part of which is applicable to B1F. To explain Case C4, it’ll help if we revisit the previous slide. Imagine that the KV-1S had started before it declared its shot. Although it would have yet to enter a new hex, it now falls under Case C4 because the vehicle is considered to be a Non-Stopped Firer. The tank does not have a Stabilized Gun so it falls under “Other.” The DRM for Case C remain unchanged at +4. What has changed is that the tank must now double the lower dr of its TH DR. Doubling the lower dr in our example increases the Final TH DR to 9, resulting in a miss.

D3.31 MG, Canister, and FT Fire

The key takeaway from this rule section is that should a vehicle fire any weapon other than its MA during the MPh, it may not fire its other weapons during the AFPh. For instance, if a tank fires its Bow MG (BMG) during the MPh, it may not fire its Coaxial MG (CMG) or its MA in the AFPh. Any Passengers or Riders aboard the vehicle are likewise restricted. All this hints at the central role an MA plays in determining what fire options a vehicle retains in the AFPh, which brings us to the next rule section.5

D3.32 Final Fire

Another concept to get your head around is what may be characterized as a sort of Bounding “Final” Fire. Strictly speaking, there is no such animal. However D3.32 does allow a vehicle that maintains Rate of Fire (ROF) during the MPh to fire its ROF weapon one additional time during the AFPh as Bounding Fire—with all the attendant restrictions of such fire (C5.3). But there’s a trade off, a big one it turns out. In accordance with D3.31, neither the vehicle nor any Passengers or Riders aboard may fire any other weapons during the MPh. This includes Small Arms Fire, the inherent Firepower (FP) of a Personnel counter. 

So what’s the payoff? Or put another way, why wait until the AFPh to fire given that the Firer-Based TH DRM will not improve? Perhaps the most important rationale for holding fire until the AFPh is that a Gun cannot acquire a target during ITS MPh (C6.5). Waiting until the AFPh also allows a vehicle (and any Passengers or Riders) to fire from a hex other than the one the MA was initially fired from during the MPh. There’s another advantage to saving a “rate” shot for the AFPh, one that will become more apparent after we examine D3.51. But there’s much to discuss before we get there. 

D3.5 Vehicular MG or IFE Fire

This section is a treasure trove of information. For our purposes though we are primarily concerned with two restrictions it places on B1F. The first restriction limits a vehicle’s weapons to one attack per player turn. There are exceptions. One is an MA with a “with a specific Multiple ROF.” The KV-1S is an example of a vehicle with this capability (identifiable by having a number encased in a square on the counter); the T-70 tankette below is not. Therefore, provided a vehicle maintains ROF, it may fire its MA again that turn. We’ll return to this point again, albeit in more detail.  

Overruns (OVR) are the other exception. As long as a vehicle has enough Movement Points (MP) to conduct an OVR, it may conduct multiple OVR during the course of ITS MPh. All still functioning vehicle weapons, together with any still applicable Passenger or Rider FP, apply to each subsequent OVR FP calculation, which is resolved on the Infantry Fire Table (IFT). The slide below explains how this works in practice.

The second restriction concerns Mandatory Fire Groups (FG). In a nutshell, if a vehicle’s weapons—together with any Passengers or Riders—want to fire at the same target during the same phase they must form a FG, in keeping with A7.55. Granted they may attack separately with ordnance, a flamethrower (FT), a Demolition Charge (DC), or with subsequent shots by a multiple ROF MA. The most common example of a Mandatory FG is an AFV that combines its BMG and CMG FP into a single attack. Similarly, a vehicle that has a weapon with an Infantry Firepower Equivalent (IFE) must FG with its MG when firing at the same target. An IFE-capable MA may only make a separate attack if it attacks as ordnance or maintains ROF. 

Passengers and Riders are a little more complicated, as the “Vegemite Sandwich” slide  demonstrates. Depending upon their conveyance and its armaments, these hitchhikers may or may not be compelled to FG. Halftrack (ht) and Carrier Passengers, for example, must (if otherwise able to) FG with their vehicle’s non-ordnance weapons. Riders, in contrast, are not required to FG with a vehicle’s weapons (D6.64). The Australian example below highlights a rare case where Riders may FG. Be that as it may, a basic rule of thumb was put succinctly by Perry Cocke, the doyen of ASL rules. “If you can FG together, then you must. If you cannot FG together, then you can fire separately.” In other words, if the rules permit the formation of a FG then a FG is mandatory when the conditions of A7.55 arise.6   

D3.51 Maintaining CA

The title of this rule section is deceptive. Its final sentence is a zinger. Players ignore it at their peril. 

At the outset of this post, Jim related how his opponent had fired the AAMG of a TD before moving to another hex and attempting to fire the AFV’s MA. This is verboten. According to D3.51: “Once any vehicular weapon fires, its other weapons may fire in that phase only from that same hex” [Emphasis added]. The rules do allow for the MA to fire again from another hex, but only if the MA maintained ROF and its previous shot was B1F. 

Jim’s opponent may have salvaged the situation had he thought to fire the MA from the same hex as the AAMG before moving to another hex. Provided the MA retained ROF, the Gun could have fired from a new hex. I know what some of you are thinking. What if the Gun didn’t maintain ROF? Is Intensive Fire (IF) an option? Yes, and no. It might be an option. However, IF can only be used to fire from the same hex that the AAMG (and the MA) fired from. Several question-and-answers (Q&A) confirm this.8

To tie a bow on this, let’s assume that the TD had fired only its MA, maintained ROF, and moved to a new hex. Upon entering the new hex the TD could fire its MA again, but not its AAMG. Were the TD to “bank” its rate shot for the AFPh, it could fire its MA once in the AFPh and gain Acquisition as a result. However, the TD still couldn’t fire its AAMG. 

More Bounding First Fire

Click to enlarge any slide


One of the greatest strengths of vehicles is their ability to shoot and move. (Or move and shoot.) Clearly this is too complex a topic to cover every possible situation in one short post. However there ought to be enough here to form a solid foundation for conducting mobile warfare. It is our hope that the foregoing examples have conveyed many of the capabilities and limitations of AFV combat, and more important, how to execute B1F properly. Just keep in mind that this has been a discussion of the mechanics of B1F shots, not the tactics.

As always, we hope this article helps in some small way. If you have questions, corrections, or suggestions for another article, let us know in the comments below. 

Until next time. — jim (and chris)


1. Ed. I’ve once again embellished and expanded upon Jim’s original post on The Bishop Says blog. I take full responsibility for any errors in the Sitrep version. The original article is available for download as a pdf on Jim's site.

2. The Advance Sequence of Play (ASOP) uses all-caps to highlight a) which unit (or group of units) is currently phasing, and b) at what stage a unit (or group of units) is in ITS MPh. A phasing unit conducts ITS MPh in three stages: START, DURING, and END. Although a unit is considered to be Moving, in the sense that it’s the unit that is actively phasing, it may not actually be moving for the purposes of A8.1. With the exception of conducting a Search, any actions undertaken by a unit at the START or END of its MPh do not qualify as moving for the purposes of Defensive First Fire, despite the fact that the unit is Moving throughout ITS MPh. These concepts are examined in more depth in Stop and Go Traffic, published here on Sitrep, and also on The Bishop Says.

3. You may find it helpful to review an earlier work of Jim's: “Infantry Target Type and Critical Hits,” as it explains why he announces his shots the way he does. See also, the pimped-out version of this article on Sitrep.

4. The Index of the ASL Rule Book describes Bounding Fire as “fire by a vehicle in the AFPh after movement to a new hex [or the use of Vehicular Bypass Movement] during the MPh [that is] used in place of—rather than in addition to—[Advancing] Fire.”

5. This is borne out by the Q&A below:

D3.3 -.32 & D3.5 

A vehicle fires its MA (only) during the MPh and keeps ROF. During its AFPh it fires one additional shot with its MA (only). Is this the only possible way a vehicle (including its PRC) can fire during both the MPh and the AFPh?

A. Yes. [Compil3]

6. In his response to questions put to him in December 2020, Perry said to expect errata for A7.55 in the future.

7. Ed. I asked Perry Cocke about this. Here is his reply, dated 12 Nov. 2021:

A7.55, D3.5, D6.64

Q. According to D6.64, the AAMG of a CE tank may form a FG with its Riders. If the AAMG and Riders form a FG and fire at a target, may the BMG or CMG subsequently fire at the same target given that neither may FG with Riders? In other words, does a player in this situation have a choice as to which weapons or units may form a FG and fire first? And if so, does this permit a second, separate attack? If not, how does one determine which weapons or units take precedence and therefore are permitted to fire? 

A. The AAMG may FG with either the other MG or with the Riders. In either case, Mandatory FG applies.

8. Here are the relevant Q&A.

C5.6, D3.3, & D3.51

In its MPh, an AFV Fires its MA and loses rate. It also fires all of its MGs from the same Location in accordance with D3.51. May the AFV declare an Intensive Fire (IF) shot? If so, may that IF shot be used to fulfill the EXC in the last sentence of D3.51 and fire that IF shot in another hex or would the IF shot limited to the Location which it has already fired from?

A. Yes. Limited. (That is, you can IF in BFF but not from a different hex.)

C5.6, D3.3, & D3.51

In a Friendly Mph, can a vehicular MA fires using Bounding First Fire, loses its rate of fire, move to another hex and then Intensive Fire? [sic]

A. No.


If a vehicle fires its MG armament, but NOT its MA, as Bounding First Fire, does one consider the MA to “maintain ROF”, so that the vehicle may move to another hex to fire its MA? Or MUST one fire the MA from the same hex as the MG, just hoping the ROF is maintained, so that the vehicle may move further and fire its MA from another hex?

A. No. Yes

9. See previous note.

10. Not firing an MA doesn’t equate to maintaining ROF. See last entry in note 8 above.

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