example for rat: reach level 2 (40 mastery), then spend 2 materials on cover.

1. <r tree rat defense: cover gives +1 ward and -1 speed. all skills have tradeoffs.
2. <r learn cover rat: pay once to learn it permanently.
3. <r loadout add cover rat: select it for your next rat run. your other choices stay selected.
4. <r loadout rat: check what that next run will start with.

you can buy and save choices during a run. they take effect when you start another run. <r loadout remove cover rat deselects cover without unlearning it. you do not need to extract to keep progress.

active runs count toward best-run, build and season leaderboards without extracting. new runs earn 1 material and 6 base mastery per defeated enemy through depth 15. at depth 16, then every 5 depths, rewards rise by 2 materials and 3 base mastery. difficulty multiplies mastery. bosses grant the same permanent fight rewards, plus loot, 6 max hp, healing and a run perk. the 3-relic difficulty unlock grants extra mastery once per difficulty. mastery and materials stay yours on death. boss healing is 12 hp or about 11% of max hp, whichever is higher. boss perks offer two uncapped combat bonuses and one recovery choice: 4 max hp (also heals 4 hp) or up to 2 supplies. when fewer than two combat bonuses remain, both recovery choices can appear. full supplies are never offered. supply rewards show the amount that fits, up to the cap of 12.

9 areas, 23 base enemies, 9 bosses, 37 events and 30 unique items. enemy traits, elements and area conditions add combinations; they are not separate base enemies or areas.

all nine areas have themed drops and their own events and bosses. regular gear can still drop there. special gear keeps its rule when upgraded; gear and compare show the rule.

broken crossings offer supplies and a condition for the next 2 fights: repair costs 3 scrap and keeps you dry, or wade for free and stay wet. wet doubles your shock damage and weakens burn, but also strengthens enemy shock. dry overrides wet terrain without removing poison fog, heat or slowing hazards. supplies stop at 12. <r buffs shows the remaining fights; the condition cannot stack or be replaced until both fights resolve. waiting, recovery, loot and fleeing do not use it up.

base enemies

rusted sentinels start with high armor that loses 20% of its starting value each round after round 1, reaching zero at round 6. shielded aliens reduce weapon/spell hits by 35% for the first 2 rounds; effect damage and counters bypass the shield. these rules change fight timing, not the number of commands. rogue foe shows the rule and stats before you act.

boss variants

new bosses can be huge, plated or swift. variants change health, armor and speed; attack and boss rules stay the same. rogue foe shows the exact stats. existing encounters keep their saved stats.