This project is not actively maintained (since many years). I no longer play or follow league. I still enjoy writing simulators, but you'll find other repositories which I've more recently written to simulate other games.

lolsim

Toy implementation of League of Legends' combat engine.

Current patch: 7.24.1.

My goal here is to familiarize myself with the finer details of LOL's rules as well as have a chance to play around with Dart.

It's difficult to imagine this ever being perfect simulation, in part because Riot does not make all of their rule values public (e.g. attack-windup, ability-durations, etc.) but also because keeping up with LOL would be a huge task.

Setup

Need a copy of Dart. Run dart bin/precache_dragondata.dart to download the necessary files from Riot's static data.

Usage

There are many entry points into the simulation used to answer different questions. Examples incude:

• dart bin/duel.dart -v examples/duel.yaml -- Used for testing groups of champs/mobs/items against one another.
• dart bin/round_robin.dart -- Used for testing all champ pairs against one another.
• dart bin/dps.dart -- Show various champs ranked by lvl 1 dps.
• dart bin/burst.dart -- Show various champs ranked by lvl 3 burst.

There are several other dart files in bin/, most of them are for testing.

Limitations

Many. Including at least:

• Champion/Item/Rune lookups are case sensitive and expect names in Title Case.
• Incomplete (and partially outdated) support for Runes.
• Very limited item support.
• Very limited abilities support.
• Limited support for Buffs.
• No CC.
• Minmal AOE or support for location or proximity.
• Limited monsters.

Questions to answer:

• Jungle clear-time approximations.
• Range catagories for each stats (high, med, low)
• Guestimate as to power ranges of various champs
• When are various items (liandries, BOTRK, etc.) worth it?
• How Burst scales?
• DPS and burst for each champ.

TODO / Bugs

• Handle stat modifying buffs first, before other buffs.
• Monster leveling
• Monsters are not neutral / incorrect AI.
• Improved proximity.
• Coverage & coveralls.io
• Split mob.dart into smaller files.
• Add more passives, abilities, runes, etc.
• Convert to integer math (ticks, etc.) to avoid double precision errors.
• Implement in-combat/out-of-combat -- More champs would die to darius and twitch dots. -- Needed for Crest of Cinders healing.
• Use round_robin json to compare lists.
• Auto-attack windup.
• Missle system & proximity.
• Neutral teams logic (do not attack until attacked, and attack as a group).
• Missing Krugs split timers.
• Krugs and Gromp Experiance on first clear.
• Healing Amp (Runic Armor, Spirit Visage, etc.)
• OnHit should not be included in lifesteal.
• Spells with duration (e.g. consume) vs. auto-attack durations.
• Buffs appear to tick 1 extra time? (Doran's Shield test)

Passives missing affecting the lvl 1 round_robin sort.

• Aatrox passive (complicated, likely requires bloodthirst to be useful)
• Akali passive (CDR interaction? Second hit on a static 4s cooldown?)
• Ashe passive (semi-complicated crit replacement) and Q
• Blitzcrank passive (needs mana and shields)
• Braum passive (needs stuns)
• Caitlyn passive (crit modifier)
• Camille passive (requires shields)
• Elise passive (ai to really use it)
• Fizz passive (unclear how to implement this kind of dmg reduction)
• Graves AA modifier and passive (impactful, hard to implement)
• Gangplank passive (small effect, needs bonus ad split)
• Kayle passive (needs percent armor mod)
• Kha'Zix passive (on-hit, small effect, with abilities bigger)
• Kled passive (very complicated, needs non-targetable)
• Malphite passive (needs shields)
• Miss Fortune passive (on hit, small effect)
• Nautalis passive (needs stun)
• Nocturn passive (aoe, unclear how best to do dmg-modified autos)
• Pantheon passive (needs blocked)
• Taric passive (needs an ability to be useful)
• Wukong passive (needs proximity)
• Sejuani passive (easy)

Plan for stuns?

• Stuns should cancel AA windups, but not AA missiles?
• Stuns prevent new AA windups during duration.

Abilities affecting round_robin / clear_times

• Alistar Trample (needs stuns)
• Ivern W brushmaker passive
• Jinx Q passive
• Rammus W ball curl
• Teemo E passive
• Udyr all of his abilities
• Vayne W passive
• Sejuani E Permafrost
• Fiddlesticks W (requires channeling)

Disclaimer

This isn't endorsed by Riot Games and doesn't reflect the views or opinions of Riot Games or anyone officially involved in producing or managing League of Legends. League of Legends and Riot Games are trademarks or registered trademarks of Riot Games, Inc. League of Legends © Riot Games, Inc.