A recurring event that REBATES a large share of resources/speedups/items you spend during its window, so the bot should TIME big spends to it. The resource consuming return is the most important: spending resources returns huge speedups (and some resources), determining whether you reach Keep 35+ without paying (e.g. consuming 2.5B of each resource returns 640+ days of speedups plus ~500M of each). FREE-to-participate (you spend items you already have). Core strategy is a cycle: START construction upgrades during a RESOURCE return event (burn resources -> get speedups), then WAIT and COMPLETE builds during a SPEED-UP return event (burn speedups -> get resources). To set up, hoard resources for half a month+: do NOT create troops/traps/construction before the event (only minimum Lv1 troops/traps for dailies). Rough Keep level able to hit each resource tier free: 125M~K25, 500M~K27, 1.25B~K29, 2.5B~K31, 5B~K33, 10B~K35 (Jan 2025 added 35B resource / 12.5M gem tiers). During SPEED-UP return events, don't overspend resources (resource-return rewards are better); spend surplus speedups on research or subordinate-city builds. Types & consumption targets: Resource (Gems, Food, Lumber, Stone, Ore); Speed-up (general/construction/healing speedups, Gems); Speed-up trap&research (Gold, trap, research speedups); Tactical Scroll; Refining Stone; Blood of Ares; Dragon feed (returns Excellent Dragon Coins); Lv7 Material (Crafting Master). Two rotations run simultaneously (11d/3d cadence). For a bot: the master rule of economy timing -- hoard, then spend during the matching return window.
Original research source: Evony Guide Wiki