Modules for the game Advanced Squad Leader (ASL) contains all the equipment needed to actually play the game. There are 14 official "core" modules that contain the essential components for a complete order of battle of all major nationalities to participate in the Second World War. Ownership of all core modules is not a prerequisite to playing the game, and as few as one module can be used. In addition to core modules, other products are also available and may be loosely referred to as "modules", or in the more specific terms as Deluxe ASL Modules and Historical ASL Modules. These required previous ownership of some of the core modules in varying combinations, or at least the components of them (rules sections and counters, and sometimes mapboards).

Each module generally contains the complete order of battle for at least one nationality, including 1/2" counters depicting infantry squads, crews, and single man counters (SMCs) as well as infantry support weapons. Some modules expanded coverage with 5/8" counters depicting vehicles and ordnance. Those modules with vehicle and ordnance counters generally also contain pages for Chapter H of the ASL Rulebook, which gives detailed notes and information on each type of vehicle or piece of ordnance.

Some modules also contain chapters specific to certain theatres, such as North Africa or the Pacific, where special rules for nationality distinctions, terrain and weather are required.

When the Finnish module "Hakkaa Päälle" was released, Advanced Squad Leader became the first tactical level wargame in history to be able to portray the armies of every nationality that participated in hostilities in the Second World War.

Core modules

Beyond Valor This initial game features all system counters necessary for playing ASL, as well as the complete infantry, vehicle and ordnance counter mix for the Germans, Russians and Finns. (A new edition published by MMP many years later added the HASL Module "Red Barricades"). The scenarios were sometimes decried as lacklustre, and mainly centered on urban combat, in keeping with the four new mapboards issued with the game. Mapboard 1 from SL and mapboard 8 from GI were necessary to play four of the ten printed scenarios as well.

Scenarios: ASL1-ASL10 Scenarios (V.3): 123-136

A 2nd Edition included additional counters for rules added in Chapter E (which was included with the 2nd Edition Rulebook), as well as changing the colour scheme for Finnish counters, and included the otherwise out of print Red Barricades HASL module, including two mapsheets, informational counters, and rulebook Chapter O).

A 3rd Edition released in December 2005 contained 10 geomorphic mapboards (done in the lighter style of the ASLSK boards), being reprints of the original Squad Leader boards 1, 2, 3 and 4, a reprint of the Cross of Iron board 5, and a reprint of board 8 from GI: Anvil of Victory, as well as reprints of the original Beyond Valor mapboards 20, 21, 22, and 23. The game also included 20 ASL scenarios and 4 six-sided dice in addition to 13 sets of counters for the complete Russian and German order of battle as well as the main system counters.

Paratrooper This game was the least expensive offering of the initial modules, containing a skeleton order of battle for United States parachute troops in Normandy and their German opponents, a small sampling of system markers, and just one mounted mapboard. The game was billed as a self-contained introductory module, and came with a rulebook chapter (Chapter K) written in conversational style that contained examples of play and a basic grounding in ASL rules for newcomers to the system. The chapter was written as a "basic training" story and included Days 1 to 6 (other days were released as part of other modules). Unfortunately, boards 1 to 4 from the original SL were still necessary to play all eight scenarios contained in the game, so either ownership of SL was required, or the boards had to be ordered separately by mail. Ownership of the ASL Rulebook was also a requirement.

Scenarios: ASL11-ASL18

A 2nd Edition deleted the Chapter K pages, as they became available with the 2nd Edition Rulebook, and added dice as well as boards 2 and 4, reissues of the boards from SL.

Yanks After the disappointment among SL fans when GI: Anvil of Victory contained no Design Your Own (DYO) unit purchase values for American forces, the third module of Yanks made up for this, for those who could afford the steep cost of this module, which had both the ASL Rulebook and Beyond Valor as prerequisites, as well as board 2 from SL, board 7 from COD and board 12 from GI (if one wanted to play the preprinted scenarios). The entire order of battle for US forces in Europe (and North Africa) was included, along with Chapter E which contained "miscellaneous" rules for amphibious landings, night fighting, air support, weather, parachute drops, glider landings, boats, convoys, swimming, ammunition vehicles, and special barrage rules for OBA (Off Board Artillery). Unfortunately, for those not interested in US forces, Chapter E would have to be purchased separately by mail order if one wanted to simulate any of these aspects with any of the other nationalities (and many printed scenarios in future modules would in fact have ownership of Chapter E a prerequisite.) Chapter H pages for US forces were also included (with DYO values and special vehicle notes describing any special in-game characteristics for each vehicle and ordnance type, as well as a brief history of each). Note that only European and North African theatre forces were included, not US forces from the Pacific theatre.

Scenarios: ASL19-ASL26

Partisan! Partisan! also required the ASL Rulebook, boards 1, 2, 3 and 4 from SL, and Beyond Valor as prerequisites to play the printed scenarios, as well as providing some counters for "Partisan" or irregular forces that could represent western European Resistance members, Yugoslavian guerrillas, or Soviet partisan troops. These partisan counters were already provided in the Beyond Valor module. The countersheet provided in Partisan! mostly gave infantry forces for Axis Minor nations (see Armies of Oblivion below) omitting any heavy weapons. A redo of board 10 from the original Rogue Series boards was included in this module, with the new artwork up to the usual high standards of the mounted mapboards of every game in the series to date, as well as a brand new board.

Scenarios: ASL27-ASL34

West of Alamein West of Alamein brought the complete order of battle for British forces to ASL, and unlike COD/GI covered the entire war, both British and US manufactured vehicles and weapons. However, the scenarios focused on North Africa, and five new mapboards as well as a large number of cardboard terrain overlays were included, along with Chapter F with several pages of special rules for simulating combat in a desert environment. Only one printed scenario included with the game required a board from a previous module (Yanks) in order to play (as well as the Chapter E rules for parachute landings), though both the rulebook and Beyond Valor were prerequisites. The module was popular for the new terrain types it brought to the game, many veteran players describing this as the "long awaited desert module." Chapter H pages for British forces were also included (with DYO values and special vehicle notes describing any special in-game characteristics for each vehicle and ordnance type, as well as a brief history of each).

Scenarios: ASL35-ASL42

Overlays: "D1-D6", "E1", "H1-H6", "S1-S8", "SD1-SD8", "W1-W4", "X1-X5".

A proposed 2nd Edition was meant to reorganize the content of this module. The 2nd Edition was to contain Chapter F for the rulebook, associated information counters, and the 5 mapboards contained in the 1st Edition. "For King and Country" replaced this 2nd edition.

The Last Hurrah The Last Hurrah brought a complete set of infantry counters for the so-called "Allied Minor" nationalities to generically represent soldiers from Poland, Norway, Belgium, The Netherlands, Greece, and some Yugoslavian forces. Prerequisites for the printed scenarios included with this module included the rulebook, Beyond Valor, and boards 2, 3 and 4 from SL. Also necessary for two of the scenarios (and not mentioned on the original packaging) was Yanks, or at the least, Chapter E which was included in that module. Another of the Rogue boards was re-released, again with updated artwork to ASL standards, as well as a new board. The third mapboard in the game was a new offering. Some unique matchups were included in the scenarios, including Polish cavalry versus German armoured cars and tanks, Yugoslavian cavalry versus German motorcycles, and Polish cavalry versus Russian armoured cars.

Scenarios: ASL43-ASL50

The module was reviewed in Volume 2, Number 15 of Wargamer (Sep-Oct 1989); Ted Bleck considered the game to be up to the usual high standards as far as components went (beautiful mounted mapboards as well as accurately printed and cut counters, easy to read and easy to separate from the "trees") but expressed disappointment at the focus of the module. No vehicles or ordnance were included (restricting play of the Allied Minors to just infantry/cavalry actions). The scenarios included were deemed to be "small by ASL standards" but fun and well balanced.

The 2nd Edition also included board 3 from the original Squad Leader series.

Hollow Legions Hollow Legions contained a wealth of exclusively new materials unseen in the Squad Leader/ASL world before. The entire order of battle for the much-maligned Italian Army was included (along with the applicable Chapter H pages providing DYO values and special vehicle notes describing any special in-game characteristics for each vehicle and ordnance type, as well as a brief history of each). Two new desert boards were provided, and prerequisites for playing the scenarios were extensive, including the rulebook, Beyond Valor, West of Alamein, and Yanks, as well as board 4 from SL, board 7 from COD and board 12 from GI. A great variety of forces made up the scenarios, however, in addition to the varied terrain, with Italian forces variously fighting against British, American, Russian and German troops.

Scenarios: ASL51-ASL58

Code of Bushido Code of Bushido was another departure for the ASL system, taking players for the first time to the Pacific Theatre of Operations (PTO).

The entire order of battle for the Japanese Army was included (along with the applicable Chapter H pages providing DYO values and special vehicle notes describing any special in-game characteristics for each vehicle and ordnance type, as well as a brief history of each). The first half of Chapter G was also included, introducing many special rules for the Japanese, as well as Pacific Theatre terrain. Four new boards were provided, representing mainly jungle terrain though using standard mapboard symbology from previous maps. Special rules converted woods to jungle, buildings to huts, etc. An extensive set of terrain overlays was also provided, much like the desert overlays in the West of Alamein module. Prerequisites for this game included the rulebook, Beyond Valor, Yanks, and West of Alamein as well as board 2 from SL. The US forces in the scenarios provided were representative of US Army units and thus no special counters or rules were needed, though the majority of scenarios dealt with Japanese troops fighting Russian, British, and Philippine partisan troops with only two situations involving American forces.

Scenarios: ASL59-ASL66

Overlays: "1-5", "B1-B5", "G1-G5", "M1-M5", "O1-O5", "RP1-RP5", "Wd1-Wd5", "X6".

In September 2013, this module was replaced by Rising Sun.

Gung Ho!