Hearthstone Battlegrounds Battle Simulator

A simulator for battles in the HS battlegrounds. This program can quickly run over a battle many times, and give statistics on the results

Example output:

Turn 8
* 4/6 Cave Hydra
* 8/2 Kaboom Bot
* 10/4 Kaboom Bot
* 11/6 Nightmare Amalgam
* 2/2 Lightfang Enforcer
* 4/6 Imp Gang Boss
VS
* 2/2 Kaboom Bot
* 2/2 Kaboom Bot
* 6/3 Cobalt Guardian, divine shield
* 2/6 Security Rover
* 4/2 Micro Machine
* 1/5 Junkbot
* 5/6 Psych-o-Tron, taunt, divine shield
--------------------------------
win: 2%, tie: 3%, lose: 94%
mean score: -6.573, median score: -7
percentiles: -14 -11 -9 -8 -8 -7 -6 -5 -4 -3 12
actual outcome: -9, is at the 20-th percentile

This corresponds to the following board state:
taken from the game at https://www.youtube.com/watch?v=TV0HSwbhasQ,

The score at the end is the number of stars of the remanining minions of the first player, or negative the stars of the second player. So a positive score means the first player wins by that many stars, a negative score means that the first player loses. This score corresponds to damage dealt or taken, excluding damage from the character's level. The program reports mean and median of the scores, and the 0%, 10%, .., 100% percentiles

Usage

hsbg run.txt

The input file consists of a series of commands to define the board state, and looks very similar to the output shown above. See examples/run1.txt.

The program can also be used in interactive mode, by starting it without any arguments. Type help to get a list of commands:

-- Defining the board
board      = begin defining player board
vs         = begin defining opposing board
* <minion> = give the next minion
HP <hero>  = tell that a hero power is used
level <n>  = give the level of a player
health <n> = give the health of a player

-- Modifying the board
give <m> <buff> = buff minion(s) m with one or more buffs

-- Running simulations
actual <i> = tell about actual outcome (used in simulation display)
run (<n>)  = run n simulations, report statistics (default: 1000)
optimize   = optimize the minion order to maximize some objective
objective  = set the optimization objective (default: minimize damage taken)

-- Stepping through a single battle
show       = show the board state
reset      = reset battle
step       = do 1 attack step, or start if battle not started yet
trace      = do steps until the battle ends
back       = step backward. can be used to re-roll RNG

-- Other
info <msg> = show a message
help       = show this help message
quit       = quit the simulator

-- Minion format
Minions are specified as
  [attack/health] [golden] <name>, <buff>, <buff>, ..
for example
 * 10/12 Nightmare Amalgam
 * Golden Murloc Tidecaller, poisonous, divine shield, taunt, windfury, +12 attack

-- Minion buffs
 * +<n> attack = buff attack by this much
 * +<n> health = buff health by this much
 * +<a>/+<h>   = buff attack and health
 * taunt, divine shield, poisonous, windfury = the obvious
 * microbots   = deathrattle: summon 3 1/1 Microbots
 * golden microbots = deathrattle: summon 3 2/2 Microbots
 * plants      = deathrattle: summon 2 1/1 Plants
 * <minion>    = magnetize given minion

-- Refering to a minion
You can refer to a minion with an index (1 to 7), a name, a tribe, or all
For example
  give all +1/+1
  give 2 poisonous  # buffs the second minion
  give Mech divine shield, windfury
  give Cave Hydra +10 health
By default this refers to your side, to modify the enemy:
  give enemy all taunt

A better user interface is a work in progress.

Compiling

To compile the code you need a recent version of gcc, python and make. Run make in the root directory to build the executable.

To make the web version you need emscripten, run make web to build it.

FAQ

Q: How do I put in a board state
A: Use a text file, see the examples directory. The plan is to eventually make a parser for the Hearthstone log files.

Q: What about Bob's tavern?
A: Currently only actual battles are simulated, the program doesn't know about buying, selling, leveling etc.

Q: What can I do with this?
A:

• You can see how lucky you are
• You can learn to better position your minions (use the optimize command)
• (future) you can see how well your board is expected to do at a certain turn of the game

Q: Known bugs
A:

• There might be subtle differences in the order of triggers etc.