KPWHYS

I saw this great video clip illustrating binomial distribution  and was reminded of a lengthy discussion I had with an engineer colleague while designing a distribution balance for loot drops. I wanted to implement a chance floor mechanic so players would not get too unlucky and he was miffed because he thought it redundant, as "everything regresses to the mean in the long run anyway". It was difficult to convince him and he had to build a simulator before understanding my point. If you set something to drop at a 20% rate per attempt, the long term average would be 5 attempts per acquisition but there would be plenty of individuals who had to make 10 attempts or more. At the extreme, given thousands of individuals, there would probably be some whom had to make 20 or more attempts to acquire said drop. The user population is unlikely to feel this when an "attempt" is very short and frequent, like a 2-3 second kill on an enemy mob with hundreds of instances in a l...

I've been working on RNG drop and specifically loot box design a lot more in recent years and I began to wonder on an essential question -- why are loot boxes so widely used in F2P games?  As a psych major, when I first started working in F2P back in 2007, I thought of loot boxes as effective purely because variable rate schedules are more effective in reinforcing behavior . This is the same mechanic that makes gambling a compelling activity, and the usage of this design is probably at the heart of all complaints about F2P games being predatory. As I was working on a loot box drop rate though, I realized I had missed an equally basic and powerful aspect of loot boxes: pricing.  Many contemporary F2P games which have loot boxes at their heart like Overwatch, AFK Arena and Empires & Puzzles often price a single loot box in the ball park of US$3. If a particular item within the loot box has a drop rate of 5%, it would take an average of 20 rolls to acquire one,...

I completed Act IV of Slay the Spire a few days ago after encountering the final boss a little less than 10 times. It's a great rogue-lite and what was interesting was how I learned one of the most important parts of the game. First, some context. Slay the Spire is a rogue-lite + deck builder mashup. In combat, players start with ~20 cards in their decks and a subset of 5 is drawn from their deck every turn. Players have a mana budget each turn and each card has its own mana cost. Used and unused cards every turn are mostly returned to a pile that can be drawn from after the initial draw pile is exhausted. At the end of most battles the player has an opportunity to choose a card from three to add to their decks. The beginner's inclination is to constantly add new cards, because most of them are pretty cool, allow combo opportunities and individually stronger than your default deck. Deck size turns out to be critical for the player because your draw size stays the same unl...

The Auto Chess genre is on fire. The original DOTA Auto Chess by Drodo Studio kicked off the storm and quickly surpassed 300,000 concurrent players . At breakneck speed, both Valve and Riot Games have launched their own Auto Chess inspired spins and both have grown very quickly . Today, it is probable that both Riot and Valve's versions have surpassed Drodo's in active players. The only piece we await in this contest is Riot's delivery of a mobile version, which will be their first successful product on mobile. As usual, Blizzard will be too late. The big question for me: Is this war over? And did Drodo let the win go? I'm a big fan of Drodo and have reached Bishop-6 on Drodo's mobile Auto Chess Origins which launched on iOS Jun 5, 2019. They've accomplished a dream of many studios to create a new genre with a massive global audience. This is a moment reminiscent of the birth of MOBA on the Warcraft 3 mod scene and history looks to repeat itself with ...