The Tavern is where you recruit generals; historic (golden) generals can appear here at level-dependent drop rates. Feature unlocks: it exists from Keep 1 (built with the Keep); Lv3 unlocks the Wheel of Fortune; Lv5 unlocks the Great General Chest; visible recruits rise with level -- 4 generals at Lv6, 5 at Lv11, 6 at Lv16 (more slots = more options per refresh). Strictly Keep-gated 1:1 (Lv1 Keep 1 ... Lv50 Keep 50). Cost F/L/S/O (Lv1 free/instant), speed +30% at Lv18 to +610% at Lv50, Power 10 (Lv1) to 62,000,000 (Lv50). Numeric historic-general drop rates live in a linked survey article, not here. For a bot, Tavern level mainly affects recruit-slot count and unlocks the Wheel of Fortune (a free daily source of speedups, stamina, VIP minutes and gathering speedups) and Great General Chest; no function is listed as disabled during upgrade. The Wheel of Fortune is a good daily-collect target.
Original research source: Evony Guide Wiki