Recently the Shop has started showing additional offers for buying seeds with gems and coins. Besides the usual 3 seed packs (for 3 different plants) containing 20 seeds sold for 5,000 coins that can be purchased once per day, the Shop now offers:
- a 5-seed packet for 3 gems
- a 10-seed packet for 10 gems
- a 5-seed packet for 1,000 coins
- a 20-seed packet for 5,000 coins
Unlike the old packets that could be purchased only once per day, there is no purchase limit on these new ones, as long as you have enough gems or coins to buy them. This changed with a data push on July 08. Now the player is limited to 1 purchase for each of these offers per day per device.
Besides the bizarre fact that the larger packets have a higher per-seed price than the smaller ones (first time I see something sold in bulk to be more expensive than selling it in smaller quantitties), people have been complaining about various problems with these offers.
One such problem (now fixed) was that sometimes these offers contained completely useless seeds for Thyme Warm and Gold Leaf – plants that cannot be upgraded with seeds – as explained in this blog post. Another problem is that the offers don't seem very random – they are often repeated, while sometimes seeds for the plant you really want to upgrade seem to never show up.
So, I decided to take a look at what these offers are and how they are constructed.
The decision seeds for which plants should be offered is taken by a pseudo-random number generator (PRNG). The seed for it (no pun intended) is stored in the data files of the game and is the same for all players, thus ensuring that everybody gets the same offers day after day. Unfortunately, I don't know which particular PRNG is used. It could be the system random library or something fancier, like Mersenne Twister.
Well, actually, not everybody gets the same offers. It turns out that the players are divided into groups, depending on their progress in Adventure mode, and they see different offers depending on which group(s) they belong to. The groups are non-exclusive – for instance, since the world progress in the game is these days strictly linear, if you belong to the group that has finished Big Wave Beach, then you obviously also belong to the group that has finished Wild West.
Here are the different groups used and the plant offers each group sees. If you belong to more than one group (which is usually the case), you'll be seeing the offers specific to all the groups you belong to.
0) Players who have not finished Ancient Egypt Day 6. They don't see any offers.
1) Players who have finished Ancient Egypt Day 6 but have not finished Wild West Day 1. They are offered seeds for the following plants:
- Bloomerang
- Grave Buster
- Iceberg Lettuce
- Bonk Choy
- Repeater
- Twin Sunflower
- Kernel-Pult
- Snapdragon
- Cherry-Bomb
- Spring Bean
- Threepeater
- Coconut Cannon
- Spikerock
2) Players who have finished Pirate Seas Day 25 (the Zomboss fight) but have not finished Wild West Day 12. They are offered seeds for the following plants:
- Twin Sunflower
- Spikerock
- Split Pea
- Chili Bean
- Lightning Reed
3) Players who have finished Wild West Day 25 (the Zomboss fight). They are offered seeds for the following plants:
- Split Pea
- Chili Bean
- Lightning Reed
- Tall-Nut
- Pea Pod
- Melon-pult
- Winter Melon
4) Players who have finished Frostbite Caves Day 1 but have not finished Frostbite Caves Day 15. They are offered seeds for the following plants:
- Tall-Nut
- Pea Pod
- Melon-pult
- Winter Melon
- Hot Potato
- Pepper-pult
- Chard Guard
5) Players who have finished Frostbite Caves Day 30 (the Zomboss fight). They are offered seeds for the following plants:
- Hot Potato
- Pepper-pult
- Chard Guard
- Stunion
- Rotobaga
6) Players who have finished Lost City Day 1 but have not finished Lost City Day 16. They are offered seeds for the following plants:
- Stunion
- Rotobaga
- Red Stinger
- A.K.E.E.
- Endurian
7) Players who have finished Lost City Day 32 (the Zomboss fight). They are offered seeds for the following plants:
- Red Stinger
- A.K.E.E.
- Endurian
- Stallia
8) Players who have finished Far Future Day 1 but have not finished Far Future Day 12. They are offered seeds for the following plants:
- Stallia
- Laser Bean
- Blover
- Citron
9) Players who have finished Far Future Day 25 (the Zomboss fight). They are offered seeds for the following plants:
- Laser Bean
- Blover
- Citron
- E.M. Peach
- Infi-nut
- Magnifying Grass
- Tile Turnip
10) Players who have finished Dark Ages Night 1 but have not finished Dark Ages Night 10. They are offered seeds for the following plants:
- Magnifying Grass
- Tile Turnip
- Sun-shroom
- Puff-shroom
- Fume-shroom
11) Players who have finished Dark Ages Night 20 (the Zomboss fight). They are offered seeds for the following plants:
- Sun-shroom
- Puff-shroom
- Fume-shroom
- Sun Bean
- Magnet-shroom
12) Players who have finished Neon Mixtape Tour Day 1 but have not finished Neo Mixtape Tour Day 16. They are offered seeds for the following plants:
- Sun Bean
- Magnet-shroom
- Phat Beet
- Celery Stalker
13) Players who have finished Neon Mixtape Tour Day 32 (the Zomboss fight). They are offered seeds for the following plants:
- Phat Beet
- Celery Stalker
- Garlic
- Spore-shroom
- Intensive Carrot
14) Players who have finished Jurassic Marsh Day 1 but have not Jurassic Marsh Day 16. They are offered seeds for the following plants:
- Spore-shroom
- Intensive Carrot
- Primal Peashooter
- Primal Wall-nut
- Perfume-shroom
15) Players who have finished Jurassic Marsh Day 32 (the Zomboss fight). They are offered seeds for the following plants:
- Primal Peashooter
- Primal Wall-nut
- Perfume-shroom
- Primal Sunflower
- Primal Potato Mine
16) Players who have finished Big Wave Beach Day 1 but have not finished Big Wave Beach Day 16. They are offered seeds for the following plants:
- Primal Sunflower
- Primal Potato Mine
- Lily Pad
- Tangle Kelp
- Bowling Bulb
17) Players who have finished Big Wave Beach Day 32 (the Zomboss fight). They are offered seeds for the following plants:
- Lily Pad
- Tangle Kelp
- Bowling Bulb
- Guacodile
- Banana Launcher
18) Players who have finished Modern Day Day 1 but have not finished Modern Day Day 16. They are offered seeds for the following plants:
- Guacodile
- Banana Launcher
- Moonflower
- Nightshade
- Shadow-shroom
19) Players who have finished Modern Day Day 32 (the Zomboss fight). Players who have finished Modern Day Day 16 but have not finished Modern Day Day 32 (the Zomboss fight). (The change was made on 2021-07-13 with a data push.) They are offered seeds for the following plants:
- Moonflower
- Nightshade
- Shadow-shroom
- Dusk Lobber
- Grimrose
As an example, suppose that your progress in Adventure mode means that you have reached Lost City Day 17. You belong to groups 3 and 5 and will be offered the following plants:
- Split Pea
- Chili Bean
- Lightning Reed
- Tall-Nut
- Pea Pod
- Melon-pult
- Winter Melon
- Hot Potato
- Pepper-pult
- Chard Guard
- Stunion
- Rotobaga
Of course, the vast majority of players have finished Adventure mode completely. This means that they belong to groups 3, 5, 7, 9, 11, 13, 15, and 17. Note that this means that they will never be offered seeds for the following plants:
- Bloomerang
- Grave Buster
- Iceberg Lettuce
- Bonk Choy
- Repeater
- Twin Sunflower
- Kernel-Pult
- Snapdragon
- Cherry-Bomb
- Spring Bean
- Threepeater
- Coconut Cannon
- Spikerock
- Twin Sunflower
- Spikerock
In addition, seeds for Sunflower, Wall-nut, and Peashooter are never offered to anyone.
Besides the above 19 groups, players can also belong to different groups depending on wheter they have bought anything for money or not – e.g., there is a group of players who have finished Dark Ages but haven't bought anything and a group of players who have finished Dark Ages but have bought at least something. However, currently both kinds of groups are treated the same.
Also, note that the above logic involving player groups applies only to these particular offers. It does not apply to the “old” 3 daily offers of 20-seed packets for 5,000 coins each.