Rules summary

Foreword

SGS Winter War is a game representing key moments of the conflict between Finland and the Soviet Union in 1939 and 1940.
SGS Afrika Korps is a game representing key moments of the conflict in the Libyan and Egyptian deserts, between the Axis and the Allies in North Africa from 1940 to 1942.
SGS Halls of Montezuma is a game depicting the Mexican American war of 1846-1848.

The rules of the Strategy Game Studio engine (or SGS for short) are tailored for strategic and operational turn-based simulation of industrial and modern conflicts. A PDF version is if needed available here.

Mapboards

Most maps of SGS games are area-based, usually with non-geometrical shapes (although we plan in the future to also use hex-based maps).
Maps are divided into individual regions, each with a name, associated terrain and possible anchors for different things like structures (e.g. cities or ports), units stacks, supply sources, information markers etc…
Regions are linked between each other by connection, of various types, movement cost, transportation types and combat effects.
Structures are elements that are present – not in all of them – inside regions. They can have extra features like the presence of an harbor (allowing ships to move in and naval supply to reach it), airport (to base air units), fortifications (fortified structures cannot be captured without a siege or an assault) or the ability to serve as supply relay (will allow the supply to extend through them).
Terrains in regions affect movement of units (all regions cost 1 only for air units, the cost varies for land units from 1 to 3 or more depending on terrain and the scale of the game), stacking of same, as well as combat, both on attack and defense factors and moral factors.

Nations and Sides

Most SGS game make 2 sides fight each other. It’s pure war, there is no diplomacy and only victory (or peace treaty handled by events, cards or end of game) can stop it.
Sides are composed of many nations, allowing to show different allies or sub-factions of a nation (e.g. we usually separate army, navy and air force units of a nation into “sub-nations”).
When a side receive replacements for its forces, it usually go to any nation part of the side, unless specified in the event or card that brings them

Scale, Events and Cards

The game scale of SGS projects can vary, with some having turns being counted in days while others could be weeks or even months. Time, distance, combat and units are all arranged to fit the chosen game scale, for different aspects such as strength, movement, number of combat rounds, game phases etc…
The game scale of SGS Winter War, SGS Afrika Korps and SGS Halls of Montezuma is weekly turns.
Each turn in the game may see (or not) the appearance of Events. Usually player will read the event description and understand what is happening. Some events may ask players to make further choices, either immediately (like location of new units entering the game) or later (which units receive reinforcements), one time or more regularly.
Each side receive a certain number of cards each turn. Cards can be played during various phases of the game (cards, movement, combat, reinforcements, end) if their conditions are met. Effects of cards are usually described in short on the card itself.

Turns and Sequence

Every game turn in SGS usually follows the same pattern, with different phases succeeding one after the other, as follows: cards, reinforcements, supply, air movement, naval movement, naval-air combat, land movement, land combat, replacement, victory check and end.
Some phases may be absent if not required or necessary (e.g. naval phase in a game without naval units) or can be present only during certain game turns (e.g. a victory check phase could be present only every second turn).

Units

There are 3 types of units in SGS: combat, support (don’t show combat factors and stay behind in battle) and leaders.
Units usually display at all times their attack, defense and movement factors, as well as their morale factor. Other factors or values can be viewed in units details windows or tooltips.
Units have life point (= strength) to account for their size and power, and stacking value (for movement). Units that lose all their life points are eliminated.
Units may receive replacements: a unit that receives one is put back to full strength in life points. Unsupplied units cannot receive replacements.

Supply

A stack is in supply if it can trace an unbroken path clear of enemy units or regions to a supply source or relay. A source is indicated on the map by the scenario supply symbol (e.g. oil barrels). A relay is usually either a friendly structure (city, airport, port, fort) or a logistical unit.
The path can be only of a certain range (in regions). Beyond that range, supply ceases to flow. In most current games, supply range is 3 or 4 (including destination region but not counting source / relay region).
Some terrain types block the movement of supply. Supply does not move through these regions, and units in them will be out of supply.
Unsupplied units will suffer from movement allowance reduction, combat value reduction, and over time life point reduction, till elimination. This process is progressive but constant over time and will result in the unsupplied unit disappearance if the situation is not remedied.

Stacking and Movement

A stack in a region can be made of a limited number of units, based on the sum of each of the stack’s individual units stacking values, the said sum being equal to or lower to the region’s stacking value (depends on the region terrain type).
Stacks move from region to region, using their movement point’s allowance, spending it according to terrain and connection costs (indicated in tooltips).
Any stack may enter a region occupied by enemy combat units if it does not exceed’s the region’s stacking value.
Stacks from multiple regions of origin may attack and enter the same enemy region, from the same and/or different directions. Multiple attacks from different directions (i.e. concentric attacks) usually give a bonus in battle.
There is no impact in battle as to when or where from a stack entered an enemy region (except if they cross certain connections like rivers or beaches). All attacking stacks will be dealt as one single stack when solving the battle. Retreating attackers however return to the region they initially entered the battle from.
You may “jump” over friendly regions that are fully or almost fully-stacked, provided you have enough movement points to cross over them and enough space (i.e. below stacking value) to enter the final destination. This principle will also apply during retreats from battle (you will jump fully-stacked friendly regions while retreating).

Combat

Combats oppose two adverse stacks in the same region.

Air battles (interceptions) are handled automatically by the game engine without player’s intervention. Air units that win the interception pursue their mission, the others abort and return to their base of origin.
Battles last a different number of rounds and are simultaneous (unless a card is played for a shoot-first effect).
The initial battle rounds are specific for air support, artillery preparation, some particular units (e.g. mines) or behavior (ambushes).
The main round is preceded by a special round for any Reconnaissance units present in some SGS games.
The main round and the following see all land units (surviving from the previous rounds) involved if they are able to fight.
After the main round, any side can retreat. The non-retreating side wins.
Each round after the main, battle exhaustion take place (battle morale is dropping): when a side reaches 0, the battle may end in rout.
The Battle Morale of each side is computed as follows: mean of the combat units’ morale + leader’s morale value + terrain effects + boosts (from cards or units, may be positive or negative).
Many modifiers (terrains, cards, various superiorities) may be applied to combat factors (or morale factors) of the units.
The most important modifiers, beside terrain and entrenchment are provided by the presence of armored units (both in attack and defense), air superiority (presence of air units) and leaders or boosters (boosters are units that give combat or moral bonus to other units in the same stack, e.g. logistical units, HQ or some special units).

Details during the Battle

In a battle round, one die (at least, may change with firepower) is rolled for each unit:
- * If the result is inferior or equal to the modified combat factor, the unit inflicts one hit to the opposing side.
- * If the result is highter than the modified combat factor, nothing happens.
  A result of 0 always inflicts a hit (no matter what modifiers apply).
Losses are inflicted automatically by the combat engine, pro-rata to the units respective strengths and weight on the battlefield, and for some units whether if they take hit first (frontline) or last (defenses).
When a unit loses half or more of her initial strength, it may become demoralized or panicked. Panicked units leave the battlefield and no longer fight (but can suffer losses in excess). Each demoralization or panic increases battle exhaustion by 1, thereby possibly shortening the battle.
In case of rout (side’s morale drops to 0 or lower and rout test fails), a pursuit may happen (a free round of fire against all routed surviving units).
In some cases where battle involves on the victorious side units able to breakthrough (such as armor, leaders, planes, mechanized troops etc…), a breakthrough may occur. In essence it gives the victor the possibility to move into an adjacent region (and start a battle there if the enemy is present). More than one successive breakthrough may occur from breakthrough battle when specific, expert, leaders are present.

Carl Nebel - Battle of Buena Vista — Carl Nebel – Battle of Buena Vista – American-mexican war.

Aviation

Aviation is obviously absent of all pre-1914 SGS games, but fairly common afterwards.

Air units move twice per turn (in first – offensive – move and last in air defense move over friendly stacks or structures) and are not stopped by enemy units except if successfully intercepted. They return to base automatically.
When air units fly over enemy structures with AA defenses, those may fire upon them (and may abort or shoot down the planes).
During their air offensive phase, they can attack enemy stacks.
During their air defense phase, they can only be move on to friendly stacks or structures (on land or at sea) to help defend them.
In either movement phase, an Air Unit can relocate (rebase) to a different Airbase. The target transfer destination will show a green halo when properly targeted.

Sieges

A fortress is a structure on map that displays a defense factor and may contain friendly units inside.

If at least 2 enemy units besiege a fortress (= present in the region outside it), a die is rolled. On a modified result equal or lower to the fortress defense factor, the latter surrenders (and units sheltered inside are eliminated).
Fortress may be assaulted: this is treated like a normal battle, but the units inside (and the fortress garrison) benefit from strong defensive bonus.

Victory

Victory Conditions are detailed for each scenario.

Usually the side with most Victory Points at the end of the scenario wins the game. There may be some “sudden death” victory (e.g. capture of the enemy’s main city or fort). Check the scenario information sheet.