Hostile Space – A Preliminary Attempt at Tabletop Game Design

Editor’s Note: I’m back after a month’s break – trying among other things to consider an appropriate topic for a new blog post!

A few months back, I was ruminating on a discussion I’d had with my friends regarding game design. Game design is a field which always seems easy when first encountered, but many hidden issues show themselves after a deeper look. Many of these issues concern the concept of game balance, whereby one player has an insurmountable advantage (or at least an advantage that is difficult to surmount) over the opposing player. Occasionally, it’s a fun exercise to try to beat the odds against you, but if the game gives a consistent advantage to certain strategies or choices to the detriment of others, it makes a lot of the game designers’ efforts redundant.

Keeping this in mind, I set myself the task of creating a game that had limited complexity in terms of setting up the game, but with the potential for complex strategies and rules once the game began. As a template, I used a concept that I had conceived of for a computer game that I wish to write; as a result, I could get a twofer where I could test the rules with human players before trying to transfer it to the computer screen. The game uses a quasi-Newtonian concept of movement, similar but probably inferior to the likes of Triplanetary. Nevertheless, if I can figure out how to refine these rules, I will endeavour to do so.

I’m making these rules available under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License; specific details are available in the copyright details underneath the rules themselves. Any suggestions for rules changes or updates would be appreciated.

HOSTILE SPACE – A game for 2 or more players
:Setting Up:

Each player begins with a set number of spacecraft (probably 4-8 in total). Each spacecraft, in turn, starts with a set number of missiles (probably 8) and a set delta-v value (probably 12-24 hexes).

The players throw a die to determine turn precedence. If two or more players receive the same amount on their die roll, these players roll again, and the order of these players is determined by this roll. The player that rolled the highest may pick a hex within the grid and place a marker there. The mark denotes an initial “zone of control” for that player, whereby the player may place their spacecraft anywhere within six hexes of that marker, and no other player may place a marker so that its zone of control would overlap that player’s zone of control. This process continues in descending order of the die rolls.

Once the spacecraft are placed, the players should remove their markers and mark their spacecraft numerically in the order they were placed. All missiles should in turn be marked with the number of the spacecraft which fired them followed by the number identifying the order in which they were fired.

:Game Rules:

Once all spacecraft have been placed and numbered appropriately, the game begins. In the first phase of each turn, the players may adjust the velocities of each of their spacecraft. Each spacecraft has a set beginning delta-v value, which determines how much they may change their velocity.

An increase or decrease in velocity in either the direction that a spacecraft is pointing or the direction opposite to the one in which the spacecraft is pointing (a “linear change” in velocity) can be resolved by subtracting the value of the difference between the number of hexes that the spacecraft would move otherwise and the number of hexes the player wishes the spacecraft to move.

For instance, if the spacecraft is travelling at a velocity of four hexes in a given direction and the player wishes the spacecraft to only travel at a velocity of two hexes in that direction, the player will spend two hexes of delta-v to decelerate the spacecraft. This may be calculated as such:

[current] 4 hexes – [proposed] 2 hexes = [delta-v cost] 2 hexes.

This rule is also applied to linear changes in velocity that would result in the spacecraft travelling in the direction opposite to the one that it is pointing. For instance, if the spacecraft is travelling with a velocity of three hexes in the direction that it is pointing, and the player wishes it to have a velocity of three hexes in the direction opposite to the direction of travel, the player will spend three hexes of delta-v to bring the velocity to zero, then three more hexes to accelerate the spacecraft in the other direction. This may be calculated as such:

[current] 3 hexes – [proposed] (-3 hexes) = [delta-v cost] 6 hexes.

If the velocity of a spacecraft is zero, the player may change the direction in which it is facing for no cost. If, however, the velocity of the spacecraft is non-zero, a change in direction costs one hex for each hex between the place where the spacecraft would end its movement at the current velocity and the proposed target, calculated in a manner of “concentric circles”. [NOTE: I’ll have to put in rules illustrating this better, if not completely rethink this section of the rules.] Calculate velocity change costs for linear velocity change first, then for directional change.

After all players have chosen their changes in velocity, the movement phase begins. Each player in order of turn precedence repositions their spacecraft in accordance with their new velocity. If at the end of movement, two spacecraft or a spacecraft and an object which occupies only a single hex are in the same hex, destroy both entities. If at the end of movement, a spacecraft is in the same hex as an object that occupies more than one hex, destroy the spacecraft. If during movement, a spacecraft would travel outside the borders, place the spacecraft at the corresponding position at the opposite side of the map and continue its movement in the current direction. [NOTE: This leads to a toroidal game area, but short of awkward rules concerning the “halfway point” of a hex grid, this is a necessary expedient.]

After the movement phase, the firing phase begins. Each player in order of turn precedence may choose to fire one missile from each of their spacecraft as long as that spacecraft has at least one missile remaining. The missile is placed in any of the hexes surrounding the spacecraft and will continue in that direction at a fixed velocity at least slightly higher than the maximum velocity of a spacecraft (approximately 15-30 hexes, based on proposed delta-v limits). Once all players have declared which spacecraft, if any, will fire, resolve the movement of each of the missiles, first by order of the players’ turn sequence, then by the order in which they were fired.

If, during movement, a single missile would pass through the hex occupied by a spacecraft or an entity occupying a single hex, destroy that missile and resolve damage if appropriate. An entity occupying a single hex is immediately destroyed, while damage to a spacecraft may be resolved under two systems: the “Brutal” system where a single hit from a missile will destroy a spacecraft, and the “Fortified” system where a spacecraft has three hit points, and on each hit from a missile, a D6 is rolled and the result modulo 3 is taken away from the spacecraft’s hit points.

If a missile would pass through a hex occupied by an entity occupying more than one hex, destroy that missile.

If, during movement, multiple missiles would pass through a hex occupied by a spacecraft or an entity occupying a single hex, determine the missile that was fired first, and on which turn it was fired. That missile, along with any others fired on the same turn, are considered to have hit and may resolve damage as normal. The remainder of the missiles pass through the hex and continue movement as normal.

The winner may be determined by the last remaining player, or by the player with the most spacecraft, or in the case of a tie, most missiles remaining after a number of turns.

:Entity placement rules:

At the beginning of the game, the players may choose to place additional game entities such as asteroids on the game map. If they choose to do so, roll either one or two D6s to determine the number of additional entities to place.

The entities are then placed on the map after the players have positioned their spacecraft. Each entity is placed one at a time on the map by the players in order of turn precedence. An entity may be placed on any hex or series of hexes on the map as long as it does not occupy or overlap a hex that is already occupied and as long as it does not overlap a player’s zone of control established by their marker or base.

:Base Defence – an alternate play style:

In the Base Defence play style, each player begins with a base, a game entity consisting of seven tokens: The central token, which occupies a single hex, and six peripheral tokens which occupy the hexes surrounding the central token. Instead of placing a marker at the start of the game, the players place their bases instead, and the central hex determines the centre of the player’s zone of control.

The objective in Base Defence is to destroy your opponent’s bases by attacking them with missiles and destroying the central token, while simultaneously defending your own. A player whose base is destroyed is considered to be defeated; any remaining base tokens, spacecraft and missiles owned by that player remain in play and all spacecraft and missiles continue at the velocity they were travelling. However, a defeated player may not change the velocity of any of their spacecraft, nor may any of their spacecraft fire any missiles.

A base does not follow the usual Hostile Space rules for entities occupying more than one hex. If a spacecraft or missile would pass through a hex occupied by a base token, both the spacecraft or missile and the base token is considered to be destroyed, and the hex occupied by the base token is then considered to be empty for the purposes of other objects passing through that hex. Once the central token of a base is destroyed, the player owning that base is defeated; see above for the consequences of defeat.

If a spacecraft ends its turn at zero velocity beside a base token owned by either the same player that owns that spacecraft or a player allied to the owner of the spacecraft, that spacecraft regains all of its expended delta-v and up to two of its expended missiles, effective on the next turn.

Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.