Build 42 Challenge Modes — The Full 42.20 Lineup and How Each One Plays

Build 42.20 ships a restructured challenge lineup. Two brand-new scenarios — Top of the World (start at the top of a skyscraper) and 28 Seconds Later (a world of sprinting zombies) — join improved returns of the classics A Really CD DA and Winter is Coming. Some older challenge maps were pulled from rotation while infection, weather and map-staging systems were retuned for the doubled map. This guide runs through the current 42.20 roster, what each challenge demands, and how challenges differ from sandbox and preset game modes. Sources: the official 42.20 "The Big Glow Up" announcement, PZwiki's Challenges page, and the new towns map guide. Checked 2026-08-09.

Note on naming: the official blog calls the sprinting-zombie scenario "28 Seconds Later"; PZwiki lists it as "28 Minutes Later." Both refer to the same world-of-sprinters scenario — the in-game menu is authoritative.

Challenge vs sandbox vs game mode

• Sandbox (and the named presets like Apocalypse, Survivor or Builder): you own the sliders — population, helicopter frequency, water shutoff, infection lore. See our sandbox settings guide and game modes guide.
• Challenge modes: designer-pre-tuned pressure cookers. Fixed (or lightly locked) weather, zombie rules, starting kit and infection twists. Fewer comfort levers, more forced lessons.
• Challenge runs are survival scenarios, not DLC content — they reuse the core game with a mutated ruleset and a themed starting situation.

The 42.20 challenge lineup

The exact roster rotates with patches — after any major update, open the challenge select screen and read each tooltip before committing, because names that existed in 42.19 may not appear on 42.20 and vice versa.

How to read a challenge before you click Start

Every challenge screen shows the scenario's baked-in differences from Apocalypse defaults. Read these three things before starting:

1. Starting state — where you spawn, what you wear, what's in your inventory. Top of the World starts you essentially empty above the loot; CD DA starts you wounded with almost nothing.
2. Zombie rules — population multiplier, speed. 28 Seconds Later flips sprinters on across the whole map, which invalidates almost every B41-based kiting habit.
3. Weather / season — Winter is Coming forces the cold loop immediately; others keep the normal July start.

Why challenges are worth running

• System practice under stress: challenges compress the survival loop (see our first-week guide) into a few in-game days, so you learn the B42 systems — crafting, foraging, combat — faster than a sandbox run.
• Map literacy: Top of the World and the map-change scenarios exercise the reworked towns and new POIs covered in the map guide.
• They are not a substitute for Apocalypse fundamentals — if you can't survive a normal first week, finish the first-week plan before attempting Extinction-style or CD DA runs.

Per-challenge tips

Top of the World — the vertical start means noise and falls are your two enemies. Clear floor by floor, barricade stairwells behind you, and don't rush the descent: the loot below is the reward, but the ground floor is where the density lives.

28 Seconds Later — sprinting zombies change everything: no kiting on foot over open ground, stealth and noise discipline matter more than combat output, and vehicles become the primary survival tool.

A Really CD DA — survive the first hours first: treat the wound, get warm, find water and a weapon before anything else. Everything after is a normal (hard) run with a much weaker start.

Winter is Coming — the cold is the real enemy. Warm clothing, indoor heat sources and the food preservation loop are not optional; plan for frozen water and reduced foraging early.

Verified on 42.20 · Last checked 2026-08-09

Challenge roster, status and hooks come from the official "The Big Glow Up" announcement (July 28, 2026) and PZwiki's Challenges page (current for 42.20.0). The "Many Years Later" map teased in the Build 42 feature list is not on the current challenge screen — treat it as not yet shipped. Per-challenge tips are community-reported play patterns, not official documentation. Exact in-game tooltips may vary by patch — the challenge select screen is authoritative.