The heart of Hollow Ground is the game's dynamic map and level system. It was designed to have a fully scalable map set. The map set can easily be extended by dropping new map files into the game's Maps folder. New maps are constantly added to the game by both the developer and users.
Level Depth Span[edit]
The Hollow Ground bunker has 40 levels. The object of the game, as mentioned above, is to find your way down to the lowest level, 2,000 feet below the surface, and deal with the biomechanical monstrosity that dwells there.
The standard map set of the game already contains more than 65 maps and is constantly growing by the contribution of many custom maps. Adding a new map does not add a new (depth) level. Maps are instead organized into level depth spans and appear randomly within such a depth span.
| Id# | Title | Depth Span | Commnet |
|---|---|---|---|
| 00 | Ground Floor | 00 | start map, always the same |
| 02 | Unsilent Grave | 01-02 | n/a |
| 03 | Doors of Perception | 01-02 | - |
| 04 | The Broken Wheel | 01-02 | - |
| 05 | Matrix Magna | 02-25 | - |
| 06 | Prison Block A | 05-20 | - |
| 07 | Prison Block B | 20-35 | - |
| 08 | Malleus Maleficarum | 02-10 | - |
| 09 | Yonic Cross | 05-15 | - |
| 10 | Smothered Hope | 02-07 | - |
| 11 | Decrepitude | 03-08 | - |
| 12 | Alien Crux | 12-25 | - |
| 13 | Devolution | 20-39 | - |
| 14 | Tomb of the Mutilated | 12-27 | - |
| 15 | Sniper Alley | 20-39 | - |
| 16 | Decay in the Morning | 02-09 | - |
| 17 | The Web | 10-35 | - |
| 18 | Tunnels of Madness | 12-27 | - |
| 19 | Grunt Inferno | 30-39 | - |
| 20 | The Vault | 10-35 | - |
| 21 | The Long and Winding Road | 10-19 | - |
| 22 | Asylum | 05-20 | - |
| 23 | Neon Lights | 15-30 | - |
| 24 | Reek of Putrefaction | 02-15 | - |
| 25 | Crystal Lake | 03-12 | - |
| 26 | Lagerhaus | 20-39 | - |
| 27 | The Minotaur | 20-39 | - |
| 28 | Solaris | 08-20 | - |
| 29 | The Abyss | 07-15 | - |
| 30 | Endless Endless | 15-35 | - |
| 31 | Hall of Mirrors | 25-39 | - |
| 32 | Black Nebula | 25-39 | - |
| 33 | Blacker than Darkness | 25-35 | - |
| 34 | Water Reservoir | 05-15 | - |
| 35 | The Cavern | 34-39 | - |
| 36 | Cthudral | 02-15 | - |
| 37 | Close to the Edge | 05-25 | - |
| 38 | Death Marines' Garrison | 05-15 | - |
| 39 | Deathcrush | 03-12 | - |
| 40 | The Downward Spiral | 25-39 | - |
| 41 | Cortex Utero | 40 | end map, always the same |
| 42 | Genocide 666 | 02-12 | - |
| 43 | Four Towers | 20-39 | - |
| 44 | Harmagedon | 20-39 | - |
| 45 | All Fools' Race | 07-20 | - |
| 46 | Aftermath | 05-15 | - |
| 47 | Blow Out | 02-15 | - |
| 48 | Rush Hour | 15-35 | - |
| 49 | Confusion is Next | 02-30 | - |
| 50 | Honeycomb | 32-39 | - |
| 51 | The Hidden | 20-30 | - |
| 52 | Claustrophobia | 10-25 | - |
| 53 | The Great Hall | 08-28 | - |
| 54 | Hatchery II | 31-39 | - |
| 55 | Overkill | 25-39 | - |
| 56 | The Hatchery I | 20-30 | - |
| 57 | The Pleasure Garden of F.S. | 02-15 | - |
| 58 | The Power Plant | 01-06 | -- |
| 59 | Prophecy | 02-10 | - |
| 60 | The Same Deep Water As You | 03-25 | - |
| 61 | The Science Lab | 15-35 | - |
| 62 | Hall of Trials | 05-15 | - |
| 63 | Acid Cave | 18-30 | - |
| 64 | The Barricades | 01-05 | revised start map |
| - | Proving Grounds | 07-15 | custom map |
| - | La Chute | 06-17 | custom map |
| - | Ex Inferis | 02-08 | custom map |
| - | Sewer Shrine | 06-16 | custom map |
| - | Alptraum Ohne Ende | 20-39 | custom map |
The order in which the maps appear is different each time you play the game. This creates a need for both a new approach to managing game difficulty and the player's strategy. Hollow Ground has a very general system for controlling the game difficulty and making sure that progressing deeper down into the bunker always delivers more of a challenge. The simple rule is that most game parameters are multiplied by the level depth span difficulty multiplier for that property. Monsters become tougher on deeper levels and generation rate increases etc. This general approach to managing game difficulty makes the order or the actual depth at which a map appear less relevant. The starter map Ground Floor for instance would be quite a challenge should its level depth span simply be changed to levels 35-39.
Maps usually appear in spans of five levels, but there is nothing preventing a map from being able to appear at any level depth. Many maps overlap one or more of the level depth layers, but it is not recommended to make maps that overlap too many layers or maps that have a level depth span that covers the entire game. The rationale behind layered maps is that game difficulty does not only depend on how tough monsters are. Game difficulty also depends on more structural conditions, that is, the tactical advantage or disadvantage created by the environment. Deeper levels more often have the player at a tactical disadvantage or require him to solve puzzles. Hollow Ground is designed so that game difficulty changes both quantitatively as well as qualitatively as you progress.
| Lvl Depth | 1-5 | 6-10 | 10-15 | 6-20 | 21-25 | 26-30 | 31-35 | 36-39 | 40 |
|---|---|---|---|---|---|---|---|---|---|
| Health | 1.0 | 1.3 | 1.6 | 1.8 | 2.0 | 2.2 | 2.4 | 2.5 | 8.0 |
| Speed | 1.0 | 1.1 | 1.2 | 1.25 | 1.35 | 1.45 | 1.55 | 1.6 | 1.7 |
| Generation | 1.0 | 1.1 | 1.2 | 1.3 | 1.4 | 1.5 | 1.6 | 1.7 | 2.0 |
The above table should give some idea of how the common properties are affected by level depth. The list is not complete. There is another parameter called Fine that affects a lot of subtle things. That and other methods that we use to balance the game are too complex to plot in a table or diagram, but work in much the same way as the Health, Speed and Generation parameters. Also, these parameters are used as variables in functions and algorithms in ways that actually make them more abstract than is conveyed by their names in the table. However, optimizing against the values in the table is a good start.
Notice: You can take any map for a test drive by holding down the ALT key as you select One Player or Two Players from the Main Menu. This enables a dialog box from which you can select any map in the Maps folder. You can also use the left and right arrow keys to select the specific level depth, within the map's level depth span, at which you would like to test the map.