Load balancing in the core game engine

In an ideal world, the game computes everything at every tick, however, this will slow the game down over time (e.g. when unit count becomes large). The game solves this by load-balancing ticks: not all actions are performed each tick, but actions are distributed across ticks.

In this article, a table is presented with a summarized form of what occurs at every tick.

One load-balance cycle is 200 ticks (0 - 199), after which count starts from 0 again.

Table of load-balanced stuff when game is running

(source: processSingleTimeTick)

Tick (0 - 199)	Function called (and key args)
0	In multiplayer, check resync by computing hashes of game data
0	Update greatest lord, but not in the first cycle of load-balancing of a match
0	Recompute sync hashes
10–18	recomputeTroopValuesForPlayer → players 0–8
25	setTreeSpreadInterval
31	createStatsPopUpEntities
34	recountTotalTroopValue
40	moatRelatedUpdateFunction
60–68	recomputeTroopValuesForPlayer → players 0–8
71–78	updateEnemyBuildings → indices 1–8
80	spawnMotherOrChild
93	recomputeTotalTroopValueOfTroopsNearKeep
95	processPeasantsForBuildings
99	showPopAndGoldPopup
101–108	recomputeTroopValuesForPlayer → players 1–8
110–149	updateWildlifeGrid → grid slice 0–39
150	updateWildlife
151	updateSection1034Info
152	updateNofFpoints
160–168	recomputeTroopValuesForPlayer → players 0–8
180	spawnChicken
190	recountStablesAndHorses

Things that are not load-balanced:

• Checking game sync status as this is performed by the host at the game time we know hashes for

• All the multiplayer message handling

Load-balancing in calendar modes

Time in the game

One load-balance cycle corresponds to a week in game time. After 200 ticks (0 - 199), the cycle is started from 0 again.

What	Ticks	Day	Week	Month	Year
Day	50	1	1/4	1/16	1/192
Week	200	4	1	1/4	1/48
Month	800	16	1/4	1	1/12
Year	9600	192	48	12	1
Load-balance cycle	200	4	1	1/4	1/48

Note: In EDITOR mode and SIEGE THAT mode, there is no concept of time. In the other game modes, time works like in the table.

Note 2: While the on-screen instruction to place keep and/or granary is showing, then weeks, months, and years are not counted yet.

Table of calendar-based balancing

Tick (0 - 199)	Function called (and key args)
0	updateCrowding
0	updateTrader
0	updateTaxing
0	updateAleRate
0	recomputeAllFearFactors
0	updateFearFactorProductivity
0	updateReligionBonuses
0	updatePopularity
0-199	(de)spawn peasants (tick the campfire clock)

More game ticks

source: processGameTick

With the calendar-based ticks out of the way, the game also balances several other computations. These occur when the game is running

Tick	What
0-199	reset counts and statistics to 0
0-199	updateWind (a wind cycle is 32 ticks)
0-199	updateClimbData (a wind cycle is 32 ticks)
0-199	updateBuildings (a wind cycle is 32 ticks)
(tick % 10) == 5	recount amount of buildings
0-199	updateBuildings
(tick % 20) == 5	apply damage to burning buildings
(tick % 20) == 3	recount amount of pitch ditches
0-199	updatePitchDitches
(tick % 10) == 8	recount amount of trees
(tick % 8) == 4	random tree (growth?)
0-199	update trees
0-199	single player events
every day	“Once more unto the breach”
every month	recompute resources in stock
every day’s 10th tick	make Outpost tribes attack
day tick == ai player id	recruit units, buy and sell goods, raid
week tick == ai player id	recruit oil duty, update tribe locations, update AI state, update taxes and rations, set food buy plan
week tick == ai player and month tick != ai player	reconsider strength/weak in Extreme trail
month tick == ai player	moat instructions, sortie units, reconsider strength/weak, destroy buildings, recruit raiding units preferably, select attack target, update recruit gold threshold status
every week	update path linkage layer, update heatmap, disappear units that can’t reach the keep
day tick == ai player	decide on new ai buildings, snooze buildings, buying plan for low resources
day tick == 8	propagate building sleep to all buildings of that type
month tick == 10	recompute heat maps
every 64 ticks	set troop value of player to 0 and recompute it
every tick	update units
every 64 ticks	assign citizen name to unit
unit dependent notice frequency	notice enemy units
every tick	update entities
every tick	remove unit chaining on same tiles
every tick	update food
every month	give food warning
every day	update population growth
every month	moving average of population
every tick	update tribe unit assignments
(tick % 32) == (tribe id % 32)	compute tribe percentage
every tick	update tribe behavior
every tick	recompute army size limit based on alive player count