Hi all, attached and copy-pasted below is the latest draft of my rules for Secret Subs, a minimalist variant for hidden sub movement that doesn’t rely on laborious bookkeeping or the honor system. It’s designed to be modular and version-agnostic. To play this variant I use these Submerged/Decoy tokens that I designed and sell on my etsy store, but you can use any set of identical tokens/chips with numbers on their face-down sides.

Let me know below what you think; and if you playtest it, how it goes!

SEPT 2022 UPDATE: Latest Rules here:
Axis_and_Allies_-_Secret_Subs_v1.0.pdf

v0.8 - DEC2021

0.1 Introduction

This is a new take on an old idea: how to at least partially simulate the ‘surprise’ nature of submarine warfare in a game with completely public information like Axis and Allies. Since the main benefit of public info games is simplicity, this variant does not seek to change that; rather we add as little secrecy as possible to preserve the “what-you-see-is-what-you-get” simplicity that makes A&A the great game it is.

Summary / TL;DR:
In this variant, each power’s submarine units are kept off-board on a public Tracker, organized into in numbered Groups. Each Group is represented on the board by a corresponding Sub ‘Token’, numbered on their bottom (secret) faces. These Tokens are placed whenever new submarines are mobilized, and they can represent groups of any size - often including zero, in which case they’re actually a decoy. On the board, Sub Tokens & decoys behave and move exactly like normal submarines, and the Group they represent is revealed only in combat.

0.2 Terminology

Before jumping into the more detailed rules, some helpful terms are defined below:

Sub Token - This is the physical “Secret Sub Token” that sits on the board/Sea Zone representing a Sub Group. Tokens have a hidden number on the bottom, which under normal circumstances may only be viewed by that Token’s owner.

Sub Group - this is the group of actual submarines that a given Token represents. Groups are organized on a power’s Sub Group Tracker, which is public knowledge. Each Group is represented on the board by the Token with the same number as that Group. Groups can be of any size, including zero.

0.3 Similarities/Differences between Sub Tokens and Fleet Markers

Sub Tokens function similarly to fleet markers from the original Axis and Allies Pacific (and the ‘marshaling cards’ from Revised) in a few ways:

1. The Tokens are each numbered for tracking (albeit secretly, in the case of Sub Tokens)
2. The actual units summarized by these Tokens are publicly visible at all times
3. The actual units summarized by these Tokens are actually present in the Token’s zone
4. Each unit summarized by the Token still must obey all normal rules

Sub Tokens are also different from Fleet Markers and marshaling cards in two key ways:

1. The ID number of each Sub Token is secret (e.g. which Token represents which Group)
2. Sub Tokens may be decoys: the group they represent may have zero submarines in it

1.0 Purchasing and Placing Secret Submarines

1.1 Each turn, powers purchase submarines as normal by paying their cost during the ‘Purchase Units’ phase and setting them aside for deployment in the mobilization zone. During the ‘Mobilize New Units’ phase these submarines are still built normally - but they are physically placed not into Sea Zones but rather onto the public Group Tracker, where they are organized into groups however their owner wishes. On the game board, these Groups will be represented by corresponding new Sub Tokens - it is these which are physically placed in the Sea Zones wherever that Group can be mobilized.

1.2 The maximum number of new Groups created (and new Sub Tokens placed) in a given turn is equal to the number of submarines purchased plus one. The new Groups/Tokens may be placed in any eligible Sea Zone, as long as all production capacity limits and rules are followed as normal.

1.3 You are not required to place all of the new Tokens available to you, but you must have at least the number needed to mobilize the new Groups you wish to create. If you do not have enough remaining free Groups on your Tracker or Sub Tokens in your supply, you may add your new subs to a group already present in the mobilization zone(s), or you may reorganize (see section 4.0 below) your Groups or remove decoy Sub Tokens from the board to free these Tokens up to be placed anew this turn.

1.4 Each Sub Token uses as many production capacity points as the number of submarines they represent, but never less than one - so decoy/empty-group Tokens still use one production capacity point each. If you do not have sufficient production capacity or Tokens to mobilize all of your eligible submarines/Tokens, they are discarded and returned to your supply.

Production Example:
John is controlling the United States, and he currently has seven Sub Groups/Tokens on the board (Groups #1-7). During this turn’s Purchase Units phase he bought three more subs. It is now the Mobilization phase, and so John is eligible to place up to four Sub Tokens (one for each purchased sub plus one extra Token. However, he only has three Tokens remaining in his supply (Groups #8-10), so he can only create up to three new Groups this turn unless he reorganizes his current Groups.

John decides to keep his current Groups as they are, and to use all three remaining Tokens. He wants to divide his three new subs into two groups - one sub in Group #8 and two subs in Group #9 - while also creating a decoy Token. To do this, he places one new submarine into the #8 box on his Group Tracker, the other two new subs into box #9, and nothing into box #10. John then places Tokens #8 & 9 into the Pacific, and he places Token #10 - the decoy with zero submarines in its Group - into the Atlantic. John’s Mobilization phase is now over, and he can move on to placing the rest of his units or the Collect Income phase.

Note that this placement strategy would consume three production capacity points from his Pacific Industrial Complex (for the two groups containing a total of three subs he placed there), and one capacity point from his Atlantic complex (for the decoy token, which still takes up one capacity point).

2.0 Secret Submarine Movement

Movement with Sub Tokens is virtually identical to moving normal submarine units. They have the same movement range and restrictions; they may stack and defend with allied and other friendly units (including yours or an ally’s other Sub Tokens), and they may move through groups of enemy ships without ASW capability (i.e. Destroyers). Just like submarines they can, if unaccompanied by surface warships, be optionally ignored during an enemy’s movement, and their presence alone does not make a Sea Zone “Hostile” for the purposes of determining legal movement or amphibious invasion points of origin (but just like subs, even decoy Tokens do prevent unescorted transports from landing troops from their Sea Zone). Two or more co-located (in the same Sea Zone) Sub Tokens/Groups may also be reorganized during movement, but never in a way that grants a sub or group additional movement.

3.0 Secret Submarine Combat

3.1 At the start of a combat involving Sub Tokens they should be moved with the rest of the participating units to the battle board, keeping their Group # hidden. If there is no opposing Destroyer present, the owners of any Sub Tokens must now choose whether their subs will submerge or fight, with the attacker choosing (and reorganizing, if desired) first, followed by the defender.

3.2 Once submerging vs. fighting Groups/Tokens have been chosen, any submerging Groups/Tokens are not revealed but are instead immediately placed back on the board face-down in the Sea Zone.

3.3 Any Groups/Tokens that are fighting (i.e. not submerging) are now simultaneously revealed. Flip them over, find their Groups on the owner’s Tracker, and place those submarines on the battle board near their respective Tokens. Keep the submarines grouped with their Tokens during combat to remember which subs belong to which Group. Combat then proceeds as normal.

3.4 Any time during combat that a submarine would submerge, they must do so as part of a Group and be represented by a Token. You may elect to have some of your subs continue fighting while others submerge, as long as you have at least one Sub Token for the submerging Group and at least one more for any subs that will remain in the combat. Place any submerging subs back on the Group Tracker, and move their Token from the Battle Board back to the Sea Zone.

3.5 If a Power has only one Sub Token or Group in a given combat, that power’s submarines must fight or submerge together as one Group.

3.6 If a revealed Token’s Group of submarines is ever zero/empty (including all decoys revealed at the start of combat), that Token is immediately discarded and returned to that owner’s supply.

3.7 At the end of combat any surviving submarine Groups are returned to the Group tracker (they may be reorganized first) and the Sub Tokens representing them are returned face-down to the Sea Zone.

Combat Example:
John (our hypothetical US player from before) wants to invade Wake Island - currently owned by Japan (which is controlled by Mike) - so during his Combat Move phase he moves a fleet to the surrounding Sea Zone. John’s invasion force includes a Battleship and two Cruisers, along with several transports and two Sub Tokens/Groups. Japan also has two Sub Tokens in that Sea Zone, as well as one Cruiser and one Destroyer.

At the start of Combat, John and Mike each move their units to the battle board, keeping their Sub Tokens unrevealed for now. John is the attacker, so he would ordinarily decide to whether to submerge subs first - but Mike has a Destroyer present, so both of John’s Sub Groups must surface and fight. John will be revealing his Sub Tokens, so he reorganizes them first. One of his two Groups was just a decoy, so to prevent it from being immediately discarded once it’s revealed he splits up his other Group and puts a few subs into the decoy Group. He leaves both of his Tokens on the battle board, and it’s now up to Mike to decide what to do.

Since John has no Destroyer present, Mike can choose to submerge his subs if he wishes. One of Mike’s Tokens is also a decoy, and the other has three subs in its Group. Mike saw John reorganize his subs, so he has a guess about how many he’s facing. He tells John that he wishes to Submerge one of his Tokens while fighting with the other. He takes the submerging Token (the decoy Token) and places it back on the board face-down in the Sea Zone. The fighting Token remains on the battle board.

Mike and John have both made their decisions, so it is time to simultaneously reveal the Groups that are going to actively fight. John reveals his Sub Tokens: #1 & 2. After his reorganization, both of those Groups now have submarines in them (he would have had to discard the decoy Token now, if he had left that Group empty). John takes the submarines off the tracker and places them near the Tokens that represent them on the battle board.

Mike also reveals the Token that has decided to fight, taking the three subs from that Group and places them on the battle board near his remaining Token. The battle can now proceed as normal, beginning with Mike’s subs’ Surprise Strike phase (since John has no destroyer).

As the combat draws to a close, Mike has one sub remaining and he decides to submerge it. He places the submarine back on the Tracker in the appropriate Group, and places that Token back in the Sea Zone next to the decoy Token that submerged at the beginning of combat. With naval combat over, John can now proceed to the amphibious invasion of Wake Island.

4.0 Secret Submarine Reorganization and Anonymization

Sub Groups may be ‘reorganized’ and ‘anonymized’ (shuffled) by their owner at any time, provided the following rules are followed:

1. Reorganization may occur at any time between Groups of submarines that are co-located and interchangeable.
Groups that are to be reorganized together must be truly interchangeable; they must be co-located and have identical movement and retreat restrictions/eligibility. If there are any gameplay-affecting differences between the groups they cannot be reorganized together.

2. Reorganization can never cause the number of Sub Tokens on the board to increase.
Sub Tokens and Groups may be consolidated and eliminated during reorganization, but new Sub Tokens and Groups cannot be created or placed as part of a reorganization. The number of Tokens/Groups after reorganization must always be equal to or less than the number of Tokens/Groups before reorganization.

3. Reorganization of Groups is public, but secret anonymization of Sub Tokens is allowed.
Sub Tokens that share a Sea Zone - even during the movement of one of the Groups - may be anonymized by their owner at any time - that is, they may be picked up from the Sea Zone and shuffled secretly, then returned to the same Sea Zone.

Reorganization Example:
John (our US player from earlier) has been building lots of submarines. He currently has eight different Sub Groups (Groups #1-8) on his tracker, and therefore he also has the eight corresponding Sub Tokens (Tokens #1-8) in various Sea Zones representing them. A maximum of 10 Sub Tokens are allowed in this game, meaning that John has only two Sub Tokens left in his supply (Tokens #9 & 10). Of the eight Groups/Tokens John has on the board, only five have actual submarines assigned to them on the Tracker. The other three do not - they’re decoys.

It is the Mobilization phase again, and John has purchased another three subs this turn. He has another four Tokens/Groups to potentially create (3 purchased subs + 1 extra)… but John only has two Tokens (#9 and 10) left in his supply. He is not required to place all four new tokens, but John likes filling up the oceans with plastic bits, so he looks at his fleet and notices that three of his Tokens/Groups (#1-3) are sharing the same Sea Zone after fighting a combat this turn. Japan just learned the composition of these three groups in a recent combat, so John decides to reorganize those Groups into one large group to free up their Tokens for new placement this turn. On his Group Tracker, then, John takes the subs out of Groups #2 and 3 and puts them all into the Group 1 box. He removes Sub Tokens #2 & 3 from the Sea Zone, leaving Token #1 alone there. John is now free to immediately create new Groups with Tokens #2 & 3 as part of his mobilization this turn.

Anonymization Example:
Continuing the above example, imagine that John has just moved one sub Token/Group into a Sea Zone that contains another of his Tokens. John decides to take this opportunity to anonymize the two Tokens to hide their identity from his opponents. To do this, John picks both tokens up off the board, shakes them up in his closed hand, and sets them back down on the board in the Zone they came from, looking at the bottom of each before doing so.

@dishero Thanks very much! Please do give it a playtest as you have time; I’m without a group to play with at the moment and the more eyes the better, of course.