Sometimes nobody is around. It is late, your friend has not answered, and you still want a game. For those times the host of a Boardit Ludo table can put a bot in an empty seat. Ludo for 2 players works well with a bot in the second chair, as long as you know what you are sitting down against. I built this bot, so I can tell you what I measured and what I did not.
How do you seat a bot?
In the lobby of a Ludo table, the settings have a Bots row with an option to add one bot, and another to fill every free seat. A bot has a name that starts with "Bot", so you can always tell it from a person. Once the game starts, the bot throws and moves for itself. It takes under a second to throw and about a second to choose a move.
You can try it at Boardit's Ludo, which is free.
How does the bot decide?
For every legal piece, the bot plays the move on a copy of the game and asks which result leaves it the highest chance of being first home. It also looks one throw further, considering what each possible next throw would do. There is one strength and no difficulty levels. Its throws come from the same game engine as yours, and its skill lies in which piece it picks.
I tried two throws ahead as well. It cost about ten times as much work for no clear gain, so the bot stays at one.
How fast is a ludo game against a bot?
Faster than against a person, because the bot never leaves you waiting. Its turns are over in a second or two, so the pace of the game is set by you. A full game is listed at 30 to 60 minutes, and against a bot most of that time is yours. Quick Ludo, with two pieces each, takes about five minutes, which makes it a natural choice for a quick session.
One caution. Because the bot answers so quickly, it is easy to click through your own turns without looking. Slow down on the turns where you have a choice of piece. That is where the game is decided.
Is the bot easy to beat?
Not really, and I would rather say so. In 3,000 computer-played two-player games, the bot won 65.5%, give or take 1.7 points, against the rule the table uses to play for an absent person. That rule is simple: take a piece if you can, otherwise bring one home, otherwise bring one out of base, otherwise move the furthest piece. It is a decent yardstick, since in 2,000 games it beat always moving the furthest piece by 78% to 22%.
So the bot is a clear step above a careless beginner. I have no measurement of how it fares against a good human player, and I would not guess. Dice still matter a great deal, and a bot can lose to a lucky six like anyone.
Why one bot and not three?
Because of the wait. The lobby itself says that a full room of bots is slower, as you sit through every bot's turn. For a two-player game the question never arises: one bot, one person, and the game keeps pace with you. If you meant to play ludo with friends and only one turned up, one bot or two is fine. Filling every seat means a slower game.
What does a game with a bot count as?
Practice. A game in which a bot played stays out of profile records, the same way a game where a bot covered an absent player does. That also means you can use a bot to learn in peace.
How can a bot help you learn?
Use it to learn the ludo rules by doing. Try Quick Ludo, with two pieces each, and play five minutes against the bot. Then try the three-tries switch and notice how the opening speeds up. Watch the log to see what the bot did on each throw, and note when it kept a pair together or moved onto a star.
When is a bot the wrong choice?
When you want company. A bot does not chat or joke. If you play ludo online for the company, send the link to a friend instead. The bot is a warm-up and a stand-in for an evening that would otherwise not happen.
Ahmed Moaz builds Boardit, a free browser game site.