Manual - Introduction to Incursion

Welcome to Incursion: Halls of the Goblin King, a promo game for the upcoming roguelike epic Incursion: Return of the Forsaken. This version of Incursion is still in alpha testing, and has limited character advancement and some unimplemented skills and features, but remains a fully playable roguelike game.

The Goal of the Game

The Forsaken — primordial mage-lords who made pacts with things beyond the rim of creation — were sealed into a ceaseless, ageless slumber eons ago during the sorcery wars. Now, their sleep grows restless and troubled, and the thirteen signs and omens the holy texts claim will presage their awakening have begun to come to pass. Trees grow crooked and bent, seven nations have fallen to the hand of one, and a crimson fire rained from the sky for three days and three nights over the town of Akrenstone. The fourth sign is a great goblin horde boiling forth from the bowels of the Earth to overwhelm a good king, and to preempt this many would-be adventurers are making the long and harsh journey to war-torn Mohandi, which holds the one known entrance to the labyrinthine underground citadel known as the Goblin Caves.

In order to win Incursion, you must create a character and advance him (or her) from 1st to 11th level, accumulating enough class abilities and magical items to be able to delve down to the tenth and final level of the Goblin Caves, wherein can be found the fortress of Murgash, the Goblin King. Slay Murgash, and the hordes of goblinoids will disperse on their own. Fail, and they will boil across the surface of Therya like a plague upon the land. Even should you succeed, you must escape with your life and return to the surface world. Do these things and you will receive the fame and glory of a hero of legend, but beware! Rumors claim Murgash is dealing with things far fouler then just goblinoids in the shadowed caverns deep beneath the stone…

Notes on Gameplay

Incursion plays significantly differently to existing roguelikes, and it's recommended that players have some experience with at least one other roguelike game before trying Incursion. Beyond this, some basic recommendations include playing a physically tough character to get a handle on the game before adventuring into the more nuanced classes. Orcs, lizardmen, dwarves, druids, rangers and paladins all make ideal choices for a new player. Halflings begin with a lot of food, which can be useful to a newbie who finds they keep running out due to resting frequently.

It is wise to map out a single level fully before diving lower, and ideally a character's level should equal or exceed the dungeon level he's currently in. Note that in Incursion, 'scumming' serves very little purpose; good items are only generated at the same time as new dungeon levels.

Ten Points for Experienced Roguelike Players

Players who have experience with other roguelike games would do well to take the following points of divergence into account:

1. Characters in Incursion do not heal simply by the passage of game turns — instead, they must use the Rest command ('z') to rest and recover, which means finding a way to be safe from encounters while you sleep. The design intent behind this is to make hit point loss a serious detriment to a player, rather than simply a nuisance. The time cycle in Incursion is different from that found in games like NetHack and Crawl, where every turn bleeds off valuable food. Players can take the time to explore and experiment, because individual turns are not that valuable, but whenever you rest, more monsters are generated in the dungeon (until it reaches equilibrium), so there is a definite pressure to accomplish as much as possible in a day.

Finding safe ways to rest is a prominent goal of any character in Incursion. Initially, a character can rest safely by returning to the surface world, and in the mid-levels of the dungeon there are special areas where one can rest safely — but eventually a character will need to rest in unsafe locales, and should strive to find a means to survive doing so.

2. List your special abilities. Most characters in Incursion have a lot of them, and they can be complex. Forgetting you have them will get you killed. They're all useful if used right. The design of Incursion is that character abilities matter more than magic items, though the latter still matter. Every ability has advantages and costs; determine how frequently you can use it and which problems it is best suited to.

3. Fountains are a valuable resource; use them wisely. A fountain can cure poison or disease and remove curses, as well as many other effects. Dipping magical items in a fountain can improve their magical plus. However, fountains can have a wide variety of negative effects as well. The behaviour of fountains is influenced by the Luck attribute; every +1 of your Luck bonus removes one possible negative effect from fountain use, starting with the most severe. Characters with a Luck bonus of +2 or higher can use a fountain without risking truly dire and irresistible consequences, though it can still provoke several dangerous effects; characters with lower Luck risk effects that can seriously mess up their game in the long term, especially in the late game.

4. Set up shortcuts. You can designate a default melee weapon, ranged weapon and ammo, and them switch between them with '-'. Once you have done this, you can fire in a cardinal direction with SHIFT+Arrow. This makes ranged combat much less tedious. Likewise, Incursion spellcasters typically operate with a wide variety of defensive spells active at any given time; use the AutoBuff feature to keep defensive spells constantly active. Likewise, assign Quick Keys to spells, Use verbs, Tactical Options and other functions you repeat frequently. All these features are discussed more thoroughly in the Interface section.

5. Incursion opposes scumming by design. This isn't meant as any kind of contempt against people who enjoy patience gaming, but it's worth being aware of — we had to cater to /some/ tastes over others, after all. When you rest, more monsters are generated, but no new treasure is generated beyond occasional items given to monsters to make them more of a threat. If you clean out dungeon levels 1-3, and have sufficient experience to move on, it's in your benefit to do so — you aren't going to keep getting more items treading water.

6. The early game in Incursion can be very difficult — you will probably die frequently — and character generation is quite detailed. The design intent behind the character generation system is that every character, even of the same race and class, will be different in some non-trivial way from others. The counterpoint of this is that its very unfair to get a really nice character (or just a truly /unique/ one), and then die to random chance right away. Likewise, much can be learned from repetition under controlled circumstances.

To accommodate this while preserving the intent for character uniqueness, Incursion implements the ability to 'reincarnate' your character after you die, starting again at level 1 with exactly the same stats, perks and random equipment you had at the beginning of the last game. A character can only be reincarnated if they died before reaching character level 5 and before descending to dungeon level 5.

7. Armor and shields both work substantially differently than they do in any of Incursion's parent systems. Armor gives a character truly significant protection, but has significant costs associated with it as well. Shields are /very/ strong, but also take up a character's active hand, preventing two-weapon fighting or wielding a weapon two-handed for increased damage. When you create a Warrior, consider very carefully what /kind/ of warrior you want to create. Incursion automatically starts very Dexterity- dependant characters with light armor, and very Strength-dependant ones with heavier armor. Read the combat chapter in the manual carefully to understand all the implications of the armor system.

8. Gods are useful. Very useful. Cultivating a relationship with one in the early game will strongly help you in the later game, both in terms of the permanent forms of blessings and bonuses you receive from your diety, and in terms of being able to pray for divine aid if you ever find yourself in a truly difficult situation. Understand the religion system, and remember that in Incursion, a few quality sacrifices count a great deal, whereas quantity accomplishes nothing.

9. Monsters are not always what they seem in Incursion. Humanoids can have classes (a dwarf rogue, for example) that aren't apparent when you first meet them; likewise, very similar or easily confused monsters cannot be told apart without special knowledge — for example, the Knowledge (Nature) skill is used to tell different breeds of dangerous fungus apart, and Sense Motive helps you determine a character's profession and skills. A 'human' might very well be a 'human scarlet disciple', and the game isn't going to tell you that until he does something to make it obvious.

The overall most dangerous and dynamic monsters in Incursion are probably your fellow humanoid adventurers — some of them are evil mercenaries serving the Goblin King, while others may provide aid to a respectable hero.

10. Plan your character build ahead of time. Choosing the right feats, spells and combination of class levels can be key to success in Incursion. We often compare Incursion to a custom-car racing game, and the analogy is apt: success depends as much on how you build your character as what you do with the character once built. Before you choose to advance in level (which you must actively do — it doesn't just happen when you get enough experience), you should already know where any feats and skill points you will recieve will be placed. If you don't, you're either still learning the game, or you haven't thought ahead enough.

A Note on Balance and Stability

Truthfully, Incursion is still very much a game in development and has not yet found its equilibrium in regard to game balance. For all I know at present, it could be nearly unbeatable without cheating, or it could become trivially easy when certain unforeseen combinations are exploited. As the developer, I welcome any feedback on how the balance issues can be addressed to produce a better game. I can be reached by my e-mail which you can find on the offical Incursion site. My life is very busy at various times, however, and I cannot promise to respond to all e-mail in a timely fashion.

As it stands, if this version of Incursion proves difficult or unplayably hard due to game balance limitations, the wizard mode can be used to adjust the difficulty of gameplay by obtaining needed items or otherwise skewing the game in favor of the player. The primary intent of this release is not to be a fully polished game, but to stand as a proof of concept for Incursion's overall design, and to provide a teaser for what's to come in the future. I encourage players to experiment with the game, try out the features and get in touch with me to offer suggestions for any future versions.

Incursion is still is very early alpha testing. It has several known game stability bugs that cause it to crash, hopefully elegantly enough to bring up a registry error dialog box, but sometimes badly enough to crash completely. Fortunately, Incursion does not delete save files until it is ready to overwrite them, so if Incursion does crash (at some place other then in the save game routines), you can recover your game from the last place you saved. What this means is that it is also in your benefit to save your game frequently, so that you don't lose a great deal when the game does crash. Incursion provides an AutoSave option for this purpose.

Frequently Asked Questions

Is Incursion based on, y'know, that popular tabletop RPG?
Yes, it is, and we think that this is one of its stronger selling points. The only reason this isn't mentioned more clearly is that the actual names are all trademarks that we can't legally use per the rules of the Open Gaming License.

Then why didn't you follow its rules more exactly?
Because that tabletop RPG was one influence of many on Incursion, not the sole guiding principle. In fact, before the OGL Incursion was imagined as a sort of unofficial sequel to the older Roguelike game Omega. This influence can still be seen in the format of the game screen, the percentile speed system and in other areas. All of the sources listed on the title page were influences on Incursion in one way or another.

Why is Incursion so buggy?
Because it's still in early alpha testing. This version was released to receive feedback, adjust game balance and polish rough edges. It's not a fully stable game yet.

Why is Incursion so slow?
My development philosophy as a programmer is that algorithms are complex enough to confuse without optimization being in the picture in an early stage of development. Premature optimization makes an already difficult task harder. Thus, for the purposes of development there are several algorithms presently in use that are decidedly suboptimal, especially in the monster AI. Incursion also performs a lot of superfluous processing each turn that will (hopefully) be eliminated in future versions. As as result, Incursion runs very, very slowly at this stage in its development. Now that the game engine is reasonably complete, greater effort will be placed toward making it run faster.

There's nothing inherently slow about Incursion's structure, it's just that code was written with an eye to clarity over speed, and 'lazy algorithms' make the game nearly unplayable on slower computers. If your processor speed is below 400 MHz, chances are that the game will become unplayable in the deeper levels, where many, many objects are onscreen at the same time. Future versions should correct this, and be fully playable on lower-end computer systems. Regardless, please try out Incursion on your system and tell me how it runs. I'm interested in how severe the slowdowns are on lower-end systems.

Is Incursion open-source?
The source will be released along with the final, true version of the game. It won't be released until then so that I can ensure exclusivity of development — in other words, I've put a tremendous amount of time and effort into writing a complex game engine, and I don't want to fully open the source right away for fear of being 'scooped' on my own game and having someone else improve/finish it their way before I have the chance to do so.

This said, it WILL be open-source eventually. You can take this as a gentleman's promise. I look forward to seeing what other people will do with my work, and would be flattered if my game was popular enough to inspire variants. I just want first crack at my own 'variant', so to speak. My expectation is that the source will thus be released around 2012, though of course dates cannot be exact.

Where can I reach the author?
My name is Julian Mensch, and the best way to get a hold of me is by e-mail which you can find on the official Incursion site. If for some reason that address isn't working, you can find my current e-mail address by Googling for newer posts by on Usenet; I use my real name there.

Where can I post messages about Incursion?
Strictly gameplay messages for any miscellaneous roguelike game are on-topic in the Usenet newsgroup Questions relating to the development (or bugs within) Incursion can be posted to the newsgroup

What's the 'resource compiler' option for?
I use it to compile the resource files (.IRC) contained in the \lib directory after editing them. If you just want to play Incursion, you don't need to do anything with it. If you want to try editing the resource files, you can then recompile MAIN.IRC and see what happens. Chances are that this won't be very fulfilling, however, as there's currently no documentation on how the IncursionScript language works, and I'm explicitly not providing technical help with scripting at this time.


All of the source code for Incursion, save what is noted below, is the work of Julian Mensch, and is fully copyright 1999-2006. However, it terms of design and gameplay Incursion owes a great deal to the other roguelike games that have come before it. The primary inspiration was Omega, and I thus owe gratitude to both Laurence R. Brothers and Erik Max Francis, for creating the only roguelike that inspired me to genuine curiosity about its world, secrets and quests. (The influence of Omega may seem tertiary at the moment; it will show more clearly once Incursion includes cities, wilderness and quests. Of course, the other major roguelikes (Angband, ToME, NetHack and ADOM) all influenced elements of Incursion as well.

The game system that Wizards of the Coast has released under the Open Game License has been greatly beneficial as well, as it forms the basis for the rules system that Incursion uses. I'd thus like to thank Gary Gygax, Monte Cook, Skip Williams, Sean K Reynolds and all of the others for producing one of the greatest hobbies in the world. Finally, a very few more specific attributions:

  • Westley Weimer has been extensively playtesting Incursion for me, doing some coding, helping me balance the game and generally being exceedingly useful. Thanks, Westley!
  • Incursion now has close to 30 playtesters, all of whom I'm very thankful to. However, I've had a truly prodigious amount of feedback from Terje S. Bo, Aaron Lambert, Adam Smith, Jussi Ylikahri, Frumple and Ivan Tomas, and the game would not have reached the state it has without their support!
  • David H. Hovemeyer placed into the public domain C++ source code for manipulating fractional values without floating-point math that proved to be most useful in the vision system.
  • Bjorn Bergstrom runs the roguelike development archive on the web, which has continually proven to be a useful resource in writing Incursion's monster AI, vision code and dungeon generator.
  • More specifically, the dungeon generator was influenced by articles written by R. Alan Monroe, Josh Tippets, Radomir Dopieralski, and others that I tragically can no longer locate to attribute.
  • Martin Minow wrote the Decus CPP C++ preprocessor and placed it in the public domain; with just a little bit of hacking this became the IncursionScript preprocessor used by the resource compiler.
  • Friedrich Wilhelm Schroeer wrote the ACCENT compiler tool (similar, but far superior to, YACC) that I used writing the IncursionScript compiler, and he too deserves credit, if only for delivering me from the purgatory of shift/reduce conflicts.
  • Jeff Heikkinen and Bradd W. Szonye developed a system for handling armor in a tabletop RPG, Draft Armor System for Cytherea, that heavily influenced how Incursion's armor works. I want to thank them for sharing this.
  • Many friendly people on the newsgroup have offered both technical advice and moral support to the roguelike development community; Timo Viitanen stands out in particular for advice for dungeon-themed roguelikes.
  • Many interesting Netbooks contain a wealth of Open Gaming Content. Incursion may contain material from: The Book of Beasts, edited by Robert J. Hall; The Netbook of Creatures, edited by Spencer Cooley; The Netbook of Feats, edited by Sigfried Trent; The Netbook of Spells & Magic, edited by Dennis Przybyla; The Netbook of Traps, edited by Adam Nave. Credit goes to the original authors and contributors.
  • The Mersenne Twister random number generator code was written by Makoto Matsumoto and Takuji Nishimura, for which I am grateful; their original copyright notice is preserved after the OGL.
  • Finally, the greatest thanks go to my father Fred Mensch, for continued support over the time that I developed this game.
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