Gaming

Tabletop maths, damage and rating systems, frame rates and the economics of in-game purchases. 41 calculators, with a solid block of D&D 5th edition tools since that is what people ask for most.

Elo rating is worth understanding beyond chess, since almost every competitive matchmaking system is a variant of it. The core of it: a 400 point gap means the stronger player is expected to win about 10 games in 11. Beat someone 400 points above you and you gain a lot. Beat someone 400 below and you gain almost nothing, which is why grinding weak opponents does not move a rating.

Gacha pity does arithmetic most players avoid doing. At a 0.6% base rate, the chance of seeing nothing in 50 pulls is about 74%, and half of players will still have nothing after 115. Hard pity counters exist because the raw probability is brutal, and seeing the number tends to change how people budget.

D&D pages follow the 5e rules as published, including the parts people house-rule. Proficiency bonus is tied to character level, not class level, which trips up multiclass builds constantly, and encounter difficulty uses the multiplier table for group size rather than raw XP totals. A party of four facing eight goblins is a harder fight than the XP sum suggests.