Old World Calculator V2.2.3 Beta

During games or Warhammer: The Old World players have to make a wide variety of strategic and tactical decisions. Having an understanding of the probable outcomes of a combat beforehand can help players make better decisions. For example:

• During list selection: Knowledge of how different equipment and option choices impact a unit's combat performance can help players build more effective armies.
• During deployment: Knowledge of how units may fare during different matchups can help players to position thier units to engage in the most optimal combats.
• During games: Where a unit has multiple potential charge targets, knowledge of the likely outcomes in each case can inform the player which (if any) is the best to engage in combat. Similarly, it can help the player receiving a charge to determine the best charge response (sometimes it may be better to run away).

Whilst some insight can be derived from looking directly at the stat-lines, equipment and special rules for different units, the complex interactions in Warhammer: The Old World are rarely straightforward to evaluate.

Experienced players will learn through practice which combats they are most likely to win or lose. However, a very large number of games are necessary to develop a comprehensive appreciation of the relative risk levels when engaging in different combats. Few, if any, players will ever accrue enough experience to develop a representative insight into the probable outcome against every enemy unit they may encounter.

Old World Calculator allows players to experiment with virtually limitless combat match-ups and review the range of outcomes over thousands of iterations, gaining a level of insight in seconds it would take years of on-table experience to develop.

Old World Calculator evaluates combats using a method known as a Monte Carlo simulation.

In simple terms, the calculator runs simulations of the combat exactly as you would play it on the tabletop. Based upon the unit sizes, formations, profiles, equipment and special rules, it works out who fights in what order, how many attacks each unit has and what they need to roll to hit, wound, save etc. It then runs through the combat, rolling pools of virtual dice to randomly determine the outcome.

Each individual simulation could go in one of any number of ways and we cannot learn much from a single iteration. However, with a large enough sample of simulated combats we can build a representative picture of the various possible outcomes and their relative probabilities.

The Old World Calculator runs 100,000 simulations for each combat to achieve a high level of accuracy in the predicted results (typically around +/- 1%).

Old World Calculator works by simulating thousands of iterations of the combat and analysing the results.

The result of each individual simulation is based upon a large number of virtual dice rolls, and is therefore random and tells us relatively little. However, by running the simulation multiple times we can produce a picture of the range of possible outcomes and their relative probabilities. The Law of Large Numbers tells us that with a large enough sample size our results will converge upon the true probability of each outcome.

Old World Calculator simulates combats 100,000 times in order to derive accurate results. However, no matter how large the sample size, the analysis is still based upon the simulation of random events, so there will always be some random noise introducing small error margins within the results.

If you run the same combat simulation multiple times on Old World Calculator you may see small variations in the results each time as a consequence of this random noise. Old World Calculator simulates sufficient sample sizes that errors are typically in the range of +/- 1%, so the impact on predicted outcomes is unlikely to have a significant bearing on your use of the calculator.

The current version of Old World Calculator is a "Beta" release.

A Beta release is a functionally operational version of a software which may still contain bugs or incomplete features.

Users should be aware that they may occassionally encounter bugs and errors when using Old World Calculator. Some bugs may result in visible error messages or obviously wrong output, however it is possible that bugs may affect calculations in less obvious ways with no visible warnings or alerts. You have been warned and I can take no responsibility if you rely upon output from the calculator in your games!

If you are concerned that a calculation may not be accurate you can run diagnostic mode to see how the calculator is simulating the combat. If there are obvious errors then please contact support@oldworldcalculator.com and copy and paste the full content of the diagnostic mode simulation into your email.

User feedback is vital to finding and eliminating bugs in the calculator. Your assistance in identifying and notifying me of such issues is greatly appreciated so that I can further improve the calculator.

Diagnostic mode is a tool designed to help identify bugs in Old World Calculator simulations.

When running diagnostic mode, the calculator will run a single simulation of the combat and will provide a detailed log of each step of the simulation. By working through the steps in the diagnostic output it is possible to determine whether the simulation has run correctly (ie, in accordance with the rules of Warhammer: The Old World) or whether it has gone awry.

If there are obvious errors in the diagnostic output then please copy and paste the full output into an email to support@oldworldcalculator.com. Your assistance in identifying and notifying me of such issues is greatly appreciated so that I can further improve the calculator.

Note that as every iteration of an Old World Calculator simulation can be different, a single diagnostic simulation may not always be sufficient to highlight all issues. If you suspect an error is occuring then it may be necessary to run the diagnostic simulation multiple times until the specific scenario which is resulting in the bug occurs.

Old World Calculator is in beta release and remains under development. As of version 2.2.0 the majority of the Universal Special Rules are now supported and can be factored into your calculations.

There remain a small number of Universal Special Rules, as well as many Army Special Rules and Unique Special Rules which are not yet supported. I am working on incorporating as many of these as possible. However, Warhammer: The Old World is an incredibly complicated game with a wide range of complex, interactive rules. Coding all of these into the calculator takes time.

Currently the simulator enables calculation of combats between two units which are assumed to be head-to-head (ie, both engaged in their front arc and centred upon each other to maximise base-to-base contact). The user can set a range of properties for each unit, including:

• Profiles for the models in each unit, including split profiles for mounted units (note: other types of split profile such as chariots are not yet supported, but I hope to add these soon).
• The total number of models in each unit.
• The width of the front rank of each unit.
• The base size of the models in each unit.
• The unit type (eg, 'Regular Infantry', 'Heavy Cavalry' etc).
• The formation of each unit (eg, 'Closed Order', 'Open Order', 'Lance' etc).
• Command groups (eg, Champions, Banner Bearers and Musicians) either in full or in part for each unit.
• The distance either unit charged (or counter charged) this round (for Initiative bonuses).
• Armour, Ward and Regeneration saves.
• Weapon Strength bonuses, Armour Piercing and Armour Bane characteristics.
• Universal Special Rules including: Ethereal, Extra Attacks, Fear, Fight in Extra Rank, First Charge, Flaming Attacks, Flammable, Frenzy, Furious Charge, Hatred, Horde, Immune to Psychology, Impact Hits, Killing Blow, Magical Attacks, Monster Slayer, Poisoned Attacks, Shieldwall, Strike First, Strike Last, Stubborn, Swiftstride, Terror, Unbreakable, Unstable, Veteran and Warband.

The above enables accurate evaluation of combats between the vast majority of units. Support for additional special rules will be added to the calculator over time.

Some special rules which are not currently directly implemented within the calculator can be easily evaluated by directly modifying other input parameters. For example, whilst the Armoured Hide (X) special rule is not directly supported, this special rule is essentially no different to equipping a unit with armour, and can be incorporated by setting the unit's Armour Value appropriately.

It is acknowledged that not all special rules can be simulated in this manner. Special rules which have more complex interactions are a priority for future development and will be implemented at the earliest opportunity. In the meantime, users should be cognisant that these special rules are not currently incorporated within the simulation and may impact on the accuracy of calculated results for affected unit types.

Not currently. This is on the list for future development.

Not currently. This is on the list for future development.