Upgrading units in Roll to Defend is the primary way to increase your defense power without relying on the randomness of the gacha wheel. While rolling gives you new units, upgrading strengthens the units you already have, providing reliable and predictable stat increases. This upgrades guide covers the complete upgrade system, level scaling mechanics, cost efficiency analysis, and when to invest in upgrades versus spending coins on rolling or zones.
The upgrade system in Roll to Defend works alongside the merging system to give you two distinct paths for strengthening your units. Upgrades use coins to increase a unit's level, while merging uses duplicate units for stat boosts. Understanding when to use each system — and how they interact — is essential for efficient progression.
How Unit Upgrades Work in Roll to Defend
Unit upgrades in Roll to Defend allow you to spend coins to increase a unit's level, which provides stat boosts to damage, health, and other attributes. Each upgrade level costs progressively more coins but provides a smaller incremental stat increase, creating a diminishing returns curve.
The upgrade process is simple: select a deployed unit, choose the upgrade option, and spend the required coins. The upgrade applies immediately and the unit's stats increase in real time. There is no upgrade cooldown, so you can upgrade multiple times in succession if you have the coins.
Upgrade Level Scaling
Each upgrade level follows a scaling pattern where costs increase exponentially while stat gains increase linearly. This means early upgrade levels provide excellent value per coin, while later levels become progressively less efficient.
| Upgrade Level | Cost (Coins) | Damage Increase | Cumulative Boost | Value Rating |
|---|---|---|---|---|
| Level 1-5 | Low (10-50) | High (+5% each) | +25% total | Excellent |
| Level 6-10 | Medium (50-200) | Medium (+3% each) | +40% total | Good |
| Level 11-15 | High (200-800) | Low (+2% each) | +50% total | Fair |
| Level 16-20 | Very High (800-3000) | Very Low (+1% each) | +55% total | Poor |
| Level 21+ | Extreme (3000+) | Minimal (+0.5% each) | +57.5%+ total | Very Poor |
The clear takeaway from this scaling curve is that levels 1-10 provide the vast majority of your upgrade value. Levels 11-20 provide diminishing returns, and levels 21+ are rarely worth the coin investment unless you have massive surplus income. For the complete upgrade priority strategy, see our Upgrade Priority Guide.
Upgrade Priority — Which Units to Upgrade First
Not all units deserve your upgrade investment. The upgrade priority in Roll to Defend follows a clear hierarchy based on unit role, rarity, and your current progression needs.
Always Upgrade First: Primary DPS Unit
Your primary DPS unit should receive the first upgrade investment because damage output directly determines wave-clear speed and income generation. Every coin spent upgrading your carry unit translates to faster wave clears, which generates more coins for further investment.
- Upgrade your primary DPS to Level 5-10 before spending on any other unit
- A fully leveled carry unit clears waves faster, earning back your investment through increased wave rewards
- Prioritize the unit with the highest base DPS — upgrades multiply base stats, so higher base stats benefit more
Upgrade Second: Tank Units
Tank units protect your carry by absorbing zombie attacks. Upgrading tanks increases their health pool, keeping them alive longer and extending your carry's uptime. A Level 5 tank provides significantly more protection than a Level 1 tank.
- Upgrade tanks to Level 3-5 after your carry is established
- Tank upgrades are most valuable when your carry is dying to zombie pressure
- A well-upgraded tank can be the difference between clearing a wave bracket and stalling
Upgrade Last: Support Units
Support units provide utility like healing or crowd control. Upgrading support units improves their utility, but the impact is generally less dramatic than upgrading DPS or tank units. Save support upgrades for when your core defense is already strong.
| Unit Role | Upgrade Priority | Target Level | Reasoning |
|---|---|---|---|
| Primary DPS | 1st | Level 10+ | Maximum damage impact |
| Tank | 2nd | Level 5-8 | Protect carry survival |
| Support | 3rd | Level 3-5 | Improve utility |
| Secondary DPS | 4th | Level 3-5 | Additional damage |
| Filler | Skip | Level 0-1 | Replace with better units |
For the detailed stage-by-stage upgrade recommendations, see our Best Upgrades for Each Stage.
Upgrade vs Merge — Which Path to Choose
Roll to Defend offers two systems for strengthening units: upgrades (spending coins) and merges (spending duplicates). Understanding when to use each system is crucial for efficient resource management.
Choose Upgrades when:
- You have coins but no duplicates — upgrades are the only way to strengthen the unit
- You need immediate power increase — upgrades apply instantly with no RNG
- Your unit is at a high base level — upgrades multiply base stats, making higher base units benefit more
- You are between rebirth cycles and need to push through a wave bracket
Choose Merges when:
- You have 3+ duplicates of a good unit — merging provides larger stat boosts per resource spent
- Your unit is low-level but you have duplicates — Merge 1 gives +30% stats for just 1 duplicate
- You want to make a mid-rarity unit competitive with higher-rarity units
- You are post-rebirth and want to quickly boost your carry
| Comparison | Upgrade (Coins) | Merge (Duplicates) | Better Choice |
|---|---|---|---|
| Power increase per resource | Moderate | High | Merge if duplicates available |
| Reliability | Guaranteed | Requires duplicates | Upgrade if no duplicates |
| Cost | Coins (common) | Duplicates (rare) | Depends on supply |
| Scaling | Diminishing returns | Also diminishing | Early levels of both are best |
In practice, the most efficient approach combines both systems: merge your carry unit first for the large +30% boost, then upgrade it to Level 5-10 for additional stat gains. This dual approach maximizes the efficiency of both resources. For the complete analysis, see our Merge vs Roll Analysis.
Upgrade Cost Efficiency — When to Stop
Understanding when to stop upgrading a unit is as important as knowing when to start. The diminishing returns curve means there is a point where spending coins on upgrades provides less value than spending them on rolling or zone purchasing.
Break-Even Analysis
The break-even point for upgrades is when the cost of the next upgrade level exceeds the income benefit it generates. If a Level 10 upgrade costs 200 coins but only increases your wave-clear speed by 2%, you need to calculate whether that 2% speed increase will generate more than 200 coins in additional income over a reasonable timeframe.
| Upgrade Level | Cost | Additional Income Generated | Break-Even Time |
|---|---|---|---|
| Level 5 | 50 coins | +10% wave speed | ~5 min |
| Level 10 | 200 coins | +6% wave speed | ~15 min |
| Level 15 | 800 coins | +4% wave speed | ~40 min |
| Level 20 | 3,000 coins | +2% wave speed | ~120 min |
The break-even times show that early upgrades pay for themselves quickly, while late upgrades require extended playtime to become profitable. As a rule of thumb, stop upgrading at Level 10-12 and redirect coins toward rolling or zone purchases unless you have massive surplus income.
Upgrades After Rebirth
After rebirth, all unit upgrades reset along with your units. However, the permanent income multiplier from rebirth makes funding upgrades in subsequent runs significantly easier. With 2x income multiplier, you can afford Level 10 upgrades on your carry unit much earlier in the rebuild process.
The post-rebirth upgrade strategy prioritizes speed. With higher luck, you pull better units faster. With higher income, you can afford upgrades sooner. The combination creates a faster rebuild curve where each post-rebirth run reaches your previous peak in a fraction of the time. For the complete rebirth strategy, see our How to Rebirth Guide.
Stage-Specific Upgrade Strategies
The optimal upgrade strategy changes as you progress through different stages of Roll to Defend. What works in the early game is not necessarily the best approach in the mid or late game. Understanding these shifts helps you allocate your coins efficiently at every point in your run.
Early Game (Waves 1-20) Upgrade Strategy
In the early game, you have limited coins and a small roster of units. The priority is getting your primary DPS unit to Level 5 as quickly as possible. This provides a substantial +25% damage boost for minimal coin investment, immediately improving your wave-clear speed and income generation.
Do not upgrade support or tank units in the early game — your coins are better spent on rolling for better units or buying Zone 2. Every coin you spend on a non-DPS upgrade in the early game delays your zone purchasing, which reduces your passive income and slows overall progression.
Mid Game (Waves 20-50) Upgrade Strategy
In the mid game, your primary DPS should already be at Level 5-8. Continue upgrading it to Level 10 if your coin income supports the cost. Once your carry reaches Level 8-10, begin investing in your tank units to Level 3-5. The tank upgrades protect your carry during the increasingly difficult wave brackets.
At this stage, you should also consider merging duplicates of your carry unit. A Merge 1 (+30% stats) combined with Level 8 upgrades provides a dramatically stronger carry unit than either approach alone. The synergy between upgrades and merges is the foundation of mid-game power.
Late Game (Waves 50+) Upgrade Strategy
In the late game, upgrade efficiency drops significantly. Levels 15+ cost enormous amounts of coins for minimal stat gains. At this point, redirect most of your coin income toward zone purchasing and rolling for rare units. Only upgrade beyond Level 12-15 if you are actively trying to push through a specific wave wall and need every possible stat point.
| Game Stage | Primary DPS Target | Tank Target | Support Target | Coins to Zones |
|---|---|---|---|---|
| Early (1-20) | Level 5-8 | Level 0-2 | Skip | 30% |
| Mid (20-50) | Level 8-12 | Level 3-5 | Level 1-2 | 40% |
| Late (50+) | Level 12-15 | Level 5-8 | Level 3-5 | 60% |
For the complete stage-by-stage guide, see our Best Upgrades for Each Stage.
Frequently Asked Questions
How do I upgrade units in Roll to Defend? Select a deployed unit and choose the upgrade option to spend coins on increasing its level. Each upgrade level provides a stat boost that improves the unit's combat performance immediately.
What is the best unit to upgrade first? Always upgrade your primary DPS unit first. Damage output directly determines wave-clear speed and income generation, making DPS upgrades the highest-impact investment per coin spent.
When should I stop upgrading and start rolling instead? Stop upgrading at Level 10-12 and redirect coins toward rolling when the cost of the next upgrade level exceeds the income benefit it generates. Early upgrade levels provide excellent value; later levels provide diminishing returns.
Do upgrades carry over after rebirth? No — all unit upgrades reset after rebirth along with the units themselves. However, the permanent income multiplier from rebirth makes funding upgrades in subsequent runs much easier and faster.
For official information about Roll to Defend, visit the Roblox game page.