Upgrade before rerolling
If a unit is placed well and already doing the job, an upgrade can be better than starting over.
- Upgrade when the wave is close to stable.
- Upgrade the unit hitting enemies longest.
- Upgrade backup if enemies die near the base.
- Do not upgrade a unit that barely touches the path.
- Retest on the same world.
Reroll before upgrading
Sometimes the team lacks a needed role.
- Reroll if early enemies leak before meaningful damage starts.
- Reroll if no unit covers the problem path well.
- Reroll when repeated upgrades do not change the wave.
- Use luck if unit quality is clearly the wall.
- Stop rerolling after a practical role upgrade.
World push decision
Push only when the current world is repeatable.
- Repeatable clear means fewer emergency fixes.
- A close messy clear is not a stable next-world signal.
- Upgrade first if the same unit saves the run every time.
- Roll first if no unit fills the missing role.
- Push after the bottleneck changes from survival to speed.